Note: It is a sad fact that most critics of the Bible know far less than they claim to. Many, if not most, non-Christians assume that Christianity is a "blind faith"... that Christians ignore reality and have unquestioning loyalty to an absolute belief system without proof or evidence. In fact, that they believe contrary to all evidence and facts. Much to the contrary, the Christian faith is a commitment based on evidence. The Judeo-Christian faith consistently stresses the importance of truth, and makes appeal to evidence to support it's truth claims. If you, or someone you know has had their faith shaken by a skeptic, I strongly suggest you take the time to read Choose Life That You Might Live.
Individual chapters include God and His Bible - The Reliability of The Old Testament The Reliability of The New Testament
The logistics behind the authorship of the Bible are truly phenomenal.
For example, it was compiled by forty independent writers who not only came from three different continents, but from vastly different backgrounds. Included among their ranks were kings, a general, at least two fishermen, farmers, a musician, a priest, a doctor, etc. Moreover, they wrote over a 1,500 year time span in more than one language and under vastly different circumstances. In most cases, they neither knew nor had any way of communicating with each other - not unless somebody had managed to build a very effective time machine.
Yet their message was centered around one theme and one theme only - man's sin and God's plan of redemption with all accompanying details - none of which contradicted any of the others in even the smallest detail. See Authorship of the Bible and Could You Write The Bible HERE
Since quite simply, this is far beyond the capabilities of even the smartest human being, one has to look further afield for an explanation. Luckily the Bible itself gives us a relatively simple explanation - its almost unbelievable unity came about because the entire book and all forty authors were inspired by God.
But what exactly does that mean?
When someone hears that the Bible was inspired of God, they are often unsure of how to understand that statement. Some take it to mean that the authors were possessed of superior insight or that they were morally and ethically exceptional human beings. Others view being 'inspired' in the same way as Monet might have been when he came across exceptionally beautiful scenery. Still others assume that the writings themselves are inspiring in the same way that a beautiful and uplifting poem can be.
Although these types of inspiration have produced some memorable literary and artistic work, Biblical inspiration is very different and very unique. In the Bible, the word 'inspiration' was translated from the Greek word theopneustos that Paul used in his second letter to Timothy.
All Scripture is inspired (Gk. theopneustos) by God and profitable for teaching, for reproof, for correction, for training in righteousness; (2 Timothy 3:16 NASB)
Theopneustos is a combination of two other words - Theos (God) and pneo (breathe). In other words, the Scriptures are God-breathed. The authors constantly reminded us that they were not the originators of the message, but instruments of revelation, i.e. the disclosure of something not previously known or realized. As Peter wrote
"for no prophecy was ever made by an act of human will, but men moved by the Holy Spirit spoke from God". (2 Peter 1:21 NASB)
Even Jesus warned that anyone who rejected His saying would be judged on the last day because His words were not His own but the Fathers
"He who rejects Me and does not receive My sayings, has one who judges him; the word I spoke is what will judge him at the last day. "For I did not speak on My own initiative, but the Father Himself who sent Me has given Me a commandment as to what to say and what to speak. (John 12:48-49 NASB)
Precision of Thought and Word
In his letter to the Corinthian church Paul claimed that both the thoughts and the words used in Scripture were all Divinely inspired,
For to us God revealed them through the Spirit; for the Spirit searches all things, even the depths of God. For who among men knows the thoughts of a man except the spirit of the man which is in him? Even so the thoughts of God no one knows except the Spirit of God.... which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, combining spiritual thoughts with spiritual words. (1 Corinthians 2:10-11, 13 NASB)
Note how, in Galatians 3:16, Paul rests his argument on the precise number of a noun
Now the promises were spoken to Abraham and to his seed. He does not say, "And to seeds," as referring to many, but rather to one, "And to your seed," that is, Christ. (Galatians 3:16 NASB)
In other words, the Bible is claimed to be a direct revelation from God, written by men who were guided by the Father Himself even to the choice of the words they used.
Revelation Came in Varied Ways.
The " word of the Lord came to Abram in a vision," (Genesis 15:1). Moses was attracted by a bush that was burning but not consumed. When he turned to investigate, he literally heard God's voice emanate from the bush (Exodus 3). Ezekiel had a series of visions (Ezekiel 1:1; 8) as did Daniel (Daniel 8 for example). Isaiah saw the Lord "lofty and exalted, with the train of His robe filling the temple" (Isaiah 6).
Others said that "the word of the Lord came" to them, a phrase that occurs over 90 times in the Bible. God's word came to Samuel (1 Samuel 15:10), to Nathan (2 Samuel 7:4), Elijah (1 Kings 18:1), Haggai (Haggai 1:3), Zechariah (Zechariah 1:1). Jeremiah mentions this happening many times as does Ezekiel.
Variations include "the Lord said," which phrase occurs over 200 times. "Thus saith the Lord" is seen over 400 times.. "the mouth of the Lord has spoken it" about 11 times. In Jeremiah 1:9 the Lord says, "Behold, I have put my words in thy mouth."
In the New Testament, Paul was converted by a vision in which God directly addressed Him. The entire end times were revealed to John in several visions that he recorded in the book of Revelation
After these things I looked, and behold, a door standing open in heaven, and the first voice which I had heard, like the sound of a trumpet speaking with me, said, "Come up here, and I will show you what must take place after these things."(Revelation 4:1 NASB)
However, most of the New Testament consists of letters written by the apostles to the earliest churches, each of which bears the personality of the one doing the writing.
Luke, who was a Gentile and a doctor did not, as far as we know, have any personal contact with Christ and therefore no first hand knowledge of the Savior. He wrote his Gospel after some very thorough research - he interviewed numerous eye witnesses and compiled all the information he received. And it seems that he had impeccable sources - Luke's Gospel is the only one of the four that tells of the events surrounding Jesus' birth from Mary's perspective. Since no one else could have known what Mary was thinking and feeling, either Luke spoke to Mary who recalled her thoughts to him, or he had to have spoken to someone very close to her whom she had confided in.
God Commanded His Words Be Written Down
In many cases, God specifically commanded His Word to be written.
Then the Lord said to Moses, "Write down these words, for in accordance with these words I have made a covenant with you and with Israel." (Exodus 34:27 NASB)
Moses recorded their starting places according to their journeys by the command of the Lord, and these are their journeys according to their starting places. (Numbers 33:2 NASB)
Then the Lord said to me, "Take for yourself a large tablet and write on it in ordinary letters: Swift is the booty, speedy is the prey. (Isaiah 8:1 NASB)
Now go, write it on a tablet before them and inscribe it on a scroll, That it may serve in the time to come As a witness forever. (Isaiah 30:8 NASB)
The word which came to Jeremiah from the Lord, saying, "Thus says the Lord, the God of Israel, 'Write all the words which I have spoken to you in a book. (Jeremiah 30:1-2 NASB)
Then the Lord answered me and said, "Record the vision and inscribe it on tablets, That the one who reads it may run. (Habakkuk 2:2 NASB)
The prophet Ezekiel could be extraordinarily precise.
It came about in the sixth year, on the fifth day of the sixth month, as I was sitting in my house with the elders of Judah sitting before me, that the hand of the Lord God fell on me there. (Ezekiel 8:1 NASB)
And the word of the Lord came to me in the ninth year, in the tenth month, on the tenth of the month, saying, "Son of man, write the name of the day, this very day. The king of Babylon has laid siege to Jerusalem this very day. (Ezekiel 24:1-2 NASB)
Note: Regarding the last quote, Ezekiel was in Babylon at the time with no way of knowing what was happening in Jerusalem. However, as further evidence of exactly when the siege of Jerusalem began, the Lord told Ezekiel to record exactly when this word form the Lord came to him. When the news from Jerusalem reached Babylon, what he wrote and the timing of the event could very soon be confirmed as true, or the writings of an someone highly imaginative. He would have been the laughing stock of the people had his claims prove to be false.
However it was accomplished - whether through dreams, visions, personal experience of one or more miracles etc., what was finally recorded was exactly what God wanted committed to posterity, which is why the Bible is called 'The Word of God'. It is simply the God's Word in print. The Spirit of God was the moving force behind the message and explains how it tells us so much that we simply would not otherwise known.
What Inspiration Was Not
We cannot be exactly sure how the Word of the Lord 'came' to these men. Moses seemed to have heard an audible voice, but then again in the spiritual world one can 'hear' sounds that are not audible - you hear them clearly in your head, but nothing reaches your ears. It is exactly the same as a vision when you clearly see something that is not visible to anyone else, nor is it seen with your physical eyes as you see the world around you.
Yet again I digress.
What is important to understand that the authors of the Bible were not stenographers who took down in shorthand word-for-word everything the Father said, and later retired to their homes to transcribe their notes. Neither did the process of inspiration bear any resemblance to 'automatic writing'. As pastor Greg Koukl amusingly but accurately wrote,
It wasn't like Paul was in a trance writing away with his eyes glued open and someone asked, "What are you writing?" And he said, "I don't know, it's Greek to me." 
Much to the contrary, the message was God's and, as we have seen, He ensured the actual words were both precise and accurate. However, since God didn't (and doesn't) use puppets the thinking, feeling human writers were actively involved. Each of them had their own personality, experiences, thoughts and feelings - to say nothing of vocabulary and style of writing. All of this was so tightly woven into the fabric of God's words that they became inseparable.
In fact, the writings themselves provide us with a small, often unnoticed, but very effective picture of how the prophets were carried along by the Spirit of God. They often began by speaking of God in the third person as any of us would do. But they soon changed to speaking in the first person - ample evidence that the Lord Himself was speaking through them. For example
The oracle concerning Egypt. Behold, the Lord is riding on a swift cloud and is about to come to Egypt; The idols of Egypt will tremble at His presence, And the heart of the Egyptians will melt within them. (2) "So I will incite Egyptians against Egyptians; And they will each fight against his brother and each against his neighbor, City against city and kingdom against kingdom. (Isaiah 19:1-2 NASB) Other examples include Hosea 6:1-4, Micah 1:3-6
What was eventually committed to parchment or papyrus was exactly what God wanted them to say. Each one accurately and without error communicated everything the Father wanted us to know.
Also See The Bible... Then And Now.
Not only do the number of manuscript copies of the New Testament far surpass the number of copies of any other ancient document, but the New Testaments 6,000 full, or partial, Greek manuscripts, the roughly 8,000 Latin translations, the copies and fragments in various other languages, and the copious quotes by early church writers, make the New Testament the best authenticated ancient document... miles ahead of any of the others. Additionally, the length of time between the original Biblical document and the earliest copies is the shortest, by far, of any ancient writing.
Perhaps the most important evidence that the Bible could not possibly have originated with man are the numerous examples of ...
It is true that many have been able to predict future events with a fair degree of accuracy. However, not only do errors occur all too often, but many predictions are so vague that they can be applied to more than one event.
The Bible makes literally hundreds of predictions of future events, some of which were general, while others were so specific that they gave places and dates. In many cases the event came about after the prophet was long gone. Whether discussing the rise and fall of empires that had not even come to power when the prophecy was written, or making prophecies about specific individuals who would not be born for many years to come (most important of whom was the Messiah), the Bible is the only 'religious' book that speaks of future events with the same certainty that it speaks of past and present events. To the best of knowledge, not a single one of these has failed to come true.
So how does this show that God is behind these prophecies? Only because neither men nor false gods can make infallible and accurate prophecies about the future. Only a Supreme Being can consistently and precisely predict the future in detail. In the book of Isaiah, the Lord says He is the first and the last, and there is no God besides Him. He asks (Emphasis Added)
"Who is like Me? Let him proclaim and declare it; Yes, let him recount it to Me in order, From the time that I established the ancient nation. And let them declare to them the things that are coming and the events that are going to take place. (Isaiah 44:6-7)
He also challenges the idol gods to "Declare the things that are going to come afterward, that we may know that you are gods". And since this is impossible for them, He then goes on to say
"Behold, you are of no account, and your work amounts to nothing; He who chooses you is an abomination." (Isaiah 41:3-4. Emphasis Added)
See Fulfilled Prophecy for some of the more outstanding ones
A second line of evidence is found in the fact that, in many cases, the authors of the Bible could not possibly have understood everything they themselves wrote - the subject matter being well beyond what was known at the time. In fact, Daniel was told to
... conceal these words and seal up the book until the end of time; many will go back and forth, and knowledge will increase." (Daniel 12:4 NASB)
It is no wonder that the Lord condemned false prophets who claimed to have been sent by Him but were, in reality, prophesying from their own imaginations. Quite obviously most, if not all, of what they said would not come to pass..
Then the Lord said to me, "The prophets are prophesying falsehood in My name. I have neither sent them nor commanded them nor spoken to them; they are prophesying to you a false vision, divination, futility and the deception of their own minds. "Therefore thus says the Lord concerning the prophets who are prophesying in My name, although it was not I who sent them--yet they keep saying, 'There will be no sword or famine in this land'--by sword and famine those prophets shall meet their end! (Jeremiah 14:14-15 NASB)
Then the word of the Lord came to me saying, "Son of man, prophesy against the prophets of Israel who prophesy, and say to those who prophesy from their own inspiration, 'Listen to the word of the Lord ! 'Thus says the Lord God, "Woe to the foolish prophets who are following their own spirit and have seen nothing. "O Israel, your prophets have been like foxes among ruins. "You have not gone up into the breaches, nor did you build the wall around the house of Israel to stand in the battle on the day of the Lord . "They see falsehood and lying divination who are saying, 'The Lord declares,' when the Lord has not sent them; yet they hope for the fulfillment of their word. (Ezekiel 13:1-6 NASB)
Inspiration and Omniscience
One has to make a careful distinction between inspiration and omniscience. In fact, the Bible makes no secret of the fact that none of the Biblical authors had infinite or total knowledge and could not have always have understood what God meant, neither in the physical nor in the spiritual realm. Here are a just a few of the many, many examples in Scripture.
The Physical Realm
Isaiah and The Universe
the prophet Isaiah lived almost 3,000 years ago and could not possibly have understood the meaning of the words that flowed from his own 'pen'...
It is He who sits above the circle of the earth, And its inhabitants are like grasshoppers, Who stretches out the heavens like a curtain And spreads them out like a tent to dwell in. (Isaiah 40:22 NASB)
It wasn't until 500 B.C. that Pythagoras first proposed that the Earth was round and, based on observations he made, Aristotle declared around 350 BC that the Earth was a sphere. However, it was the ancient Greek astronomer Eratosthenes who not only discovered the Earth was round, but made the first models and maps based on a spherical Earth. He even accurately calculated the size of the earth! However, Eratosthenes was only born in 276 BC.
Additionally, it wasn't until 1925, that the American astronomer Edwin Hubble (whom the Hubble Space Telescope is named after) proved that the universe is expanding, and that there is a direct relationship between the speeds of distant galaxies and their distances from Earth
The Paths of The Sea
The eighth Psalm refers to the "paths of the sea" which, more than likely, refers to ocean currents. Interestingly these were only discovered by man in the 1850’s. It is a historical fact that Matthew Fontaine (1806-1873) "who wrote the first textbook on modern oceanography called The Physical Geography of the Sea and Its Meteorology, was a Christian who had no doubts about the accuracy of the Bible. After an accident partially disabled him ending his active duty with the Navy, he was appointed superintendent of the US Naval Observatory in Washington. "In his Bible studies, the words of Psalm 8 stuck in his mind: ‘ ... whatsoever passeth through the paths of the seas'. Maury determined that if God's Word said there were 'paths' in the seas, then there must be paths. So he set out to find them. 
And so he did. He searched for and found the great sea lanes traveled by modern vessels.. He was able to develop charts of the ocean currents (the 'paths' of the seas) which greatly aided the science of marine navigation.
But one has to ask how Job could possibly written about ocean currents which he, nor anyone else living at the time, had absolutely no knowledge about.
The Empty Place
Job 26:7 says, ""He stretches out the north over empty space and hangs the earth on nothing.
Using some incredibly powerful telescopes modern astronomers see a solid mass of stars surrounding the earth - with one exception..
The universe has a huge hole in it that dwarfs anything else of its kind. The discovery caught astronomers by surprise. The hole is nearly a billion light-years across. It is not a black hole, which is a small sphere of densely packed matter. Rather, this one is mostly devoid of stars, gas and other normal matter, and it's also strangely empty of the mysterious "dark matter" that permeates the cosmos. Other space voids have been found before, but nothing on this scale. 
This "gap" is in the Northern Hemisphere, lying in the general direction of the constellation Bootes is a 300 million light year gap in the distribution of galaxies that has taken cosmologists by surprise, not because it exists, but because it is so big.
Indeed, He stretches out the north over the empty place.
At the time man was totally ignorant of gravity and had absolutely no idea that the earth was suspended in space. Yet, thousands of years ago Job was able to make a pronouncement that would not be fully understood until centuries in the future.
And this is only the tip of the iceberg.
See Scientific Facts In The Bible
Compelling scientific evidence that the Bible is no ordinary book
The Spiritual Realm
Peter and the Gentiles
For example, on the day of Pentecost, Peter who was addressing the Jews who were gathered in Jerusalem for the Feast, said
"For the promise is for you and your children and for all who are far off, as many as the Lord our God will call to Himself." (Acts 2:39 NASB)
Considering that the Jews were completely convinced that the Messiah had come to free them from the yoke of tyranny in the land God had promised them, it is impossible the Peter would have grasped the far reaching implications of his own words. Yet, just a few years and one miracle later, Peter himself took the message to the "far off" Gentiles.
Paul and Original Sin
An even more outstanding examples is when, in Romans 5, Paul makes a direct connection between the sin of Adam and the fallen condition of the entire race. He seems to be saying that something happened to all humanity because of what transpired in the garden of Eden.
The fact is that Paul Himself couldn't have understood what it meant when the Lord said the entire race was affected by the sin of Adam. And, for centuries, neither could we. But, in spite of the fact that innumerable other verses (Footnote I) that clearly and unambiguously tell us that no person can bear the guilt (or innocence) of another, did we chalk it up to one of the things that we do not understand?
No, of course not.
Instead in our infinite 'wisdom', we decided that the only thing Paul could have been referring to is what is now called 'Original Sin' - Adam's legacy to all his descendants is a moral corruption that causes every member of the human race to be born guilty of sin long before they commit one for themselves.
Except we are dead wrong. The relatively new emerging field of Epigenetics seems to strongly indicate what Paul was talking about 2000 years ago. It also goes a long way in explaining what the Born Again experience may be. See Original Sin or Epigenetics
The Authors Were Not Sinless...
We cannot assume that because the authors of Scripture were hand-picked by God, they were perfect human beings. As John wrote
If we say that we have no sin, we are deceiving ourselves and the truth is not in us. (1 John 1:8 NASB)
Paul, the author of two third of the New Testament said this
but I discipline my body and make it my slave, so that, after I have preached to others, I myself will not be disqualified. (1 Corinthians 9:27 NASB)
... But Just as Human As The Rest of Us
Although all these men are portrayed as spiritual giants the Bible does not hesitate to tell us that ...
Noah got drunk shortly after he vacated the ark (Genesis 9:21), Abraham lied about Sarah being his sister (Genesis 12:13, 20:2), Moses, the author of the first five books of the Old Testament, had an apparent outburst of anger in the wilderness (Numbers 20:10-12), murdered a man in Egypt, and was very reluctant to approach the Pharaoh, as the Lord commanded. The beloved king David was documented as an adulterer who had his lover's husband murdered (2 Samuel 11).
And when God instructed Jonah to go to Nineveh with a warning to the people there, he fled in the opposite direction. (This, if you think about it, was not right, but perfectly understandable. Many of his countrymen had already experienced carnage at the hands of the cruel and merciless Assyrians. What God told Jonah to do could be compared with telling a mid 20th century Jew to go preach to the Gestapo. and while I have heard many Christians get up on their high horses and point their fingers at the disobedient prophet, God was not quite as quick to condemn.. He dragged Jonah back to fulfill the original mission but was also very kind to the prophet taking great trouble to show Jonah what compassion meant.
In the New Testament, not only did the disciples rather childishly argue about which one of them was the greatest (Luke 22:24), fall asleep on the crucial night before Jesus' trial even though He had asked them to watch and pray (Mark 14:32-41), but also ran away when Jesus was arrested (Mark 14:50). Additionally, when confronted, Peter denied knowing Jesus (Matthew 26:72).
Later on, Peter stopped eating with the Gentiles for fear of the Jews (Galatians 2:11-12), Paul and Barnabas argued about whether Mark should accompany them on one of their missionary journeys (Acts 15:37-39), and Paul's confessed that he was "foremost" of sinners (1 Timothy 1:15).
The fact that the Bible does not attempt to hide or gloss over the misdeeds of its central characters, nor attempt to portray them in a favorable light, certainly reinforces the case that it is an honest book that tells of people who, in spite of their great faith, could be just as human as any of us.
 God Doesn't Give Autographs. www.str.org/articles/god-doesn-t-give-autographs
 Matthew Maury's search for the secret of the seas. Answers in Genesis.
 Mitchell Waldrop, Delving the Hole in Space, Science Magazine, Nov. 27, 1981.
Passages of Scripture that unambiguously tell us that no person can bear the guilt (or innocence) of another ... that every one will answer for their own sins and misdeeds. For example (Emphasis Added)
"Fathers shall not be put to death for their sons, nor shall sons be put to death for their fathers; everyone shall be put to death for his own sin. (Deuteronomy 24:16 NASB)
Now it came about, as soon as the kingdom was firmly in his hand, that he killed his servants who had slain the king his father. But the sons of the slayers he did not put to death, according to what is written in the book of the Law of Moses, as the LORD commanded, saying, "The fathers shall not be put to death for the sons, nor the sons be put to death for the fathers; but each shall be put to death for his own sin." (2 Kings 14:5-6 NASB) Also See 2 Chronicles: 25:4
"Yet you say, 'Why should the son not bear the punishment for the father's iniquity?' When the son has practiced justice and righteousness and has observed all My statutes and done them, he shall surely live. "The person who sins will die. The son will not bear the punishment for the father's iniquity, nor will the father bear the punishment for the son's iniquity; the righteousness of the righteous will be upon himself, and the wickedness of the wicked will be upon himself. (Ezekiel 18:19-20 NASB)
"Therefore I will judge you, O house of Israel, each according to his conduct," declares the Lord GOD. "Repent and turn away from all your transgressions, so that iniquity may not become a stumbling block to you. (Ezekiel 18:30 NASB)
"Yet you say, 'The way of the Lord is not right.' O house of Israel, I will judge each of you according to his ways." (Ezekiel 33:20 NASB)
"In those days they will not say again, 'The fathers have eaten sour grapes, And the children's teeth are set on edge.' "But everyone will die for his own iniquity; each man who eats the sour grapes, his teeth will be set on edge. (Jeremiah 31:29-30 NASB)