Index to All Nine Chapters
Unlike most other Christians who believe that the human soul is separate and distinct from the physical body, the Jehovah's Witness contend that humans are souls thus completely cease to exist at the moment of physical death, i.e. there isn't a spiritual component that continues to exist after a person dies.
They further maintain that the belief that the body dies but the soul lives on is a "later origin" - a concept that "owes more to Greek philosophy than to biblical revelation.”  They also say that
"The sure promise of the resurrection - not the teaching of the immortality of the soul — is the basis for real hope for the dead". 
An immortal soul, if it existed, would need no resurrection, since immortality precludes death.... Jesus even demonstrated the Biblical teaching of the resurrection by raising people from the dead. Take the example of Lazarus, who was dead for four days. When Jesus resurrected him, Lazarus came out from the tomb a living, breathing human. No immortal soul slipped back from heavenly bliss into his body when Lazarus awoke from the dead. If that were the case, Jesus would hardly have done him a favor by resurrecting him! John 11:39, 43, 44. 
The second statement is partially accurate inasmuch as the soul is not immortal. And certainly Jesus did Lazarus a disservice if his soul had already entered "heavenly bliss". Except this is not exactly what happened.
However, the first order of business is whether or not our soul is a spiritual entity separate from our body.
Are Body and Soul Two Separate Components?
In describing the creation of the first human beings Genesis says
Then the Lord God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being. (Genesis 2:7 NASB)
In other words, something had to be put into the body to bring it to life. Thus it only makes sense that when a person dies, the reverse takes place, i.e the breath of life departs from the body. The Jehovah's Witnesses do not deny this but answer the question of what made that material body come to life with
It was God's blowing into man's nostrils, thus into man's lungs, the "breath of life." It was not by his breathing into man an invisible soul and connecting that soul with the material body... 
In other words, Adam was a combination of the body and God's breath of life. Their simple equation is "human soul = body + breath of life from God". 
But is this true?
If man completely ceases to exist when he dies, what are we to make of Ecclesiastes 12:7 - "then the dust will return to the earth as it was, and the spirit will return to God who gave it".
Also, in the following passage Jesus made it very clear that the soul survives death, even when the body is killed which, without doubt or question, should tell us that the soul and body are not the same thing. The verse also explains why, when they were stoning him to death, Stephen "called on" the Lord Jesus to receive his spirit! (Acts 7:59 NASB)
Do not fear those who kill the body but are unable to kill the soul; but rather fear Him who is able to destroy both soul and body in hell. (Matthew 10:28 NASB)
It is also more than interesting to note that in the three accounts of our Lord raising the dead He approached the dead person and spoke to them as if they were alive - not exactly something one does with corpses.
When Jesus saw the only son of a widow was dead and being carried out of the city, He felt compassion for the mother, came up to the coffin, touched it and said, "Young man, I say to you, arise!"
When Christ entered the house of a synagogue official whose daughter was dead, He, "took her by the hand and called, saying, "Child, arise!" (Luke 8:54 NASB)
Finally, although Mary and Martha's brother had been dead four days, Jesus had the stone removed and "cried out with a loud voice, "Lazarus, come forth." (John 11:43 NASB)
So if the soul does outlive the body one has to ask for how long, i.e. is it immortal? Most Christians seem to think so.
Is The Soul Immortal?
Based on the fact that the Bible says God created mankind in His own image, Christian theologian Norman Geisler says
Were God to annihilate human beings he would be attacking himself, for we are made in his image (Genesis 1:27) and God is immortal, thus we have to be just as immortal as He is. 
(More about this in Making Excuses for God - How Christians Justify Their Misinterpretation of Scripture
Regardless of how confident the above statement sounds, there is absolutely nothing in the Bible that tells us what being made "in God's image" exactly means. It is possible that our emotions, our ability to love etc. may be examples of how we are made in God's image, but all we can be certain of is that since God does not have a physical body we cannot be patterned after His physical likeness. Anything else is opinion and conjecture.
In fact, the Bible never once says, nor even implies, that the soul is immortal and imperishable. Much to the contrary Paul very clearly stated that God alone possesses immortality.
who alone possesses immortality and dwells in unapproachable light, whom no man has seen or can see. To Him be honor and eternal dominion! Amen. (1 Timothy 6:16 NASB)
However, it is in the Father's hands to bestow immortality (i.e. eternal life) on those who follow Him, but we need to also remember that He can and will destroy both body and soul.
"Do not fear those who kill the body but are unable to kill the soul; but rather fear Him who is able to destroy both soul and body in hell. (Matthew 10:28 NASB)
And as the Father said in Ezekiel,
"Behold, all souls are Mine; the soul of the father as well as the soul of the son is Mine. The soul who sins will die. (Ezekiel 18:4 NASB)
Believing in an immortal soul has opened the doors to the idea of an eternal hell. Think about it! The traditional view of hell means that "everyone has eternal life; it's only a matter of where each will spend it" - (either in heaven or hell). This doesn't make a whole lot of sense when one considers (among many other facts) the question asked of Jesus in Matthew 19:16. The man was asking what he had to do to obtain eternal life, not what he had to do to ensure he spent it in a good place.- and Jesus didn't correct him.
And behold, one came to him and said, Teacher, what good thing shall I do, that I may have eternal life?
Also see Those Overlooked Greek Words. Part IV of What and Where is Hell?
Where Does The Soul Go When A Person Dies?
As mentioned above, the Jehovah's Witnesses say that when he died had Lazarus' soul departed to be with God, Jesus did him no favors by resurrecting him because that meant that his soul would have had to leave heaven and re-inhabit his body.
There is an enormous amount of confusion, misunderstanding and, let's face it, incorrect and unscriptural opinions when it comes to the matter of where the soul goes when it departs our physical bodies. Yet, it really is a very simple issue. Where a person's soul goes when he or she dies depends on several factors - whether they died before or after Jesus' resurrection and whether they were believers or not.
Before Jesus' Resurrection
The Seven Feasts of Israel not only celebrated a historical event in Israel's past but were also a prophecy of future events that concern us all. In fact, the historic and prophetic significance of the Feasts is one of the most fascinating of all Biblical studies. They were types that, in Christian theology, are actual historical events that were a rough draft or a glimpse, of one or more events yet to occur. In other words, one or more event (or person) foreshadowed, pointed to, and culminated in one final and very important event (or person) called the antitype. See The Seven Feasts of Israel
The feast of First fruits was the fifth of the feasts that was observed on the 17th day of Nisan. It was a celebration of the harvest, when a sheaf representing the very first of the harvest was waved before the Lord, as a symbolic gesture that dedicated the coming harvest to Him.
Jesus rose from the dead on the Feast of First-fruits. His resurrection was the wave offering presented to the Father as the first-fruits of the harvest to come at the end of the age. The Apostle Paul said...
But now Christ has been raised from the dead, the first fruits of those who are asleep. For since by a man came death, by a man also came the resurrection of the dead. For as in Adam all die, so also in Christ all will be made alive. But each in his own order: Christ the first fruits, after that those who are Christ's at His coming, (1 Corinthians 15:20-23 NASB)
If Jesus was the first fruits of a vast harvest to come, no one - but no one could have preceded Him to heaven. Everyone who dies prior to His resurrection simply went to Sheol - the grave. And please note that Sheol and Hades are EXACTLY the same place demonstrated by the fact that when the New Testament writers quoted a passage from the Old Testament that used the Hebrew Sheol, they used the Greek Hades in its place. Here is an example,
For You will not abandon my soul to Sheol; Nor will You allow Your Holy One to undergo decay. (Psalms 16:10)
because you will not abandon my soul to Hades, nor allow your Holy One to undergo decay. (Acts 2:27)
See Sheol And Hades
After Jesus' Resurrection
Where one's soul goes depends on whether one is a believer or not.
When believers die their soul immediately departs the body and goes to God. As Paul said
For to me, to live is Christ and to die is gain. (Philippians 1:21 NASB)
we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord. (2 Corinthians 5:8 NASB)
This heaven or God's throne room is not the final destination of the soul that simply has to wait until it can return to earth with Christ and be reunited with a resurrected body at the Seventh Trumpet DETAILS. We can know this because in more than one place in the New Testament, we are told that the Lord will not return alone. Matthew, using the Greek word aggelos (messenger), said He will return with His angels to administer judgment.
But when the Son of Man comes in His glory, and all the angels (Gk. aggelos) with Him, then He will sit on His glorious throne. "All the nations will be gathered before Him; and He will separate them from one another, as the shepherd separates the sheep from the goats; (Matthew 25:31-32 NASB)
However, Jude spoke of the Lord coming with His Holy Ones using the word hagios,
It was also about these men that Enoch, in the seventh generation from Adam, prophesied, saying, "Behold, the Lord came with many thousands of His holy ones (Gk. hagios), to execute judgment upon all, and to convict all the ungodly of all their ungodly deeds which they have done in an ungodly way, and of all the harsh things which ungodly sinners have spoken against Him." (Jude 1:14-15 NASB)
In the book of Thessalonians Paul clearly stated that the hagios who return with Christ will be believers
so that He may establish your hearts without blame in holiness before our God and Father at the coming of our Lord Jesus with all His saints (Gk. hagios). [1 Thessalonians 3:13 NASB]
See more on Jesus' Second Coming and The Resurrection of The Body - Part III of What And Where is 'Heaven'?
Also note that God does not have (and never had) any intention of permanently maintaining a heaven somewhere 'up there' - quite separate from earth. Much to the contrary, the Bible shows that not only did God visit earth, but the Tabernacle was built as God's "dwelling place", one that He intended to live in forever. Details in A New Heaven and A New Earth - Part IV of What And Where is 'Heaven'?..
The Old Testament Righteous
The question that obviously springs to mind is what happened to the righteous people of the Old Testament who followed God but had never heard of Jesus. Ephesians 4:8 says
Therefore it says, "when He ascended on high, He led captive a host of captives, and he gave gifts to men." (Now this expression, "He ascended," what does it mean except that He also had descended into the lower parts of the earth? He who descended is Himself also He who ascended far above all the heavens, so that He might fill all things.) (Ephesians 4:8-10 NASB)
Although, admittedly this is a difficult verse, no two people seem to have the same idea of what it means. The opinions range from He may have gone to Tartarus - the place of confined demonic spirits (no idea why He would), the 'captives' were the enemies of Israel (why would he set them free?) etc. etc.
However, the explanation is really not that difficult - after Christ died He "descended into the lower parts of the earth" i.e. Sheol. (not Tartarus) where everyone except for church age believers goes. (As mentioned earlier Sheol and Hades are EXACTLY the same place). It is entirely possible that this is when He preached deliverance to "the captives" or the righteous people of God. In which case, they too will return to earth with Christ and be able to reclaim their physical bodies. See Section Above
At the beginning of His ministry, Jesus described His mission by paraphrasing Isaiah 61:1. He said,
"The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised." (Luke 4:18)
The underlined part of Ephesians 4:8 very possibly refers to the same event.
In most people's Bibles this verse reads as Jesus promising that the thief would be with Him in paradise that very day.
And he said to him, "Truly, I say to you, today you will be with me in Paradise."
This obviously implies that the thief would continue to live in some way after his physical body died. However, this clashes with Jehovah Witness doctrine so they simply changed the punctuation in their version of the Bible placing the comma after "today" - rather than before it. Their version reads,
And he said to him, "Truly I tell you today, you will be with me in Paradise." 
This simple change completely alters the meaning of Jesus' words, i.e Jesus was not promising that the man would be in paradise that very day, but He was speaking on that day of a time in the undefined future when the thief would be in paradise with Him. The emphasis was placed on the time that the promise was being made rather than on when it would be fulfilled.
The fact that there were no punctuation marks in the original Greek allows the Jehovah's Witnesses to assert that the translator placed the comma according to his own bias and pre-suppositions. But, the reverse can also be true - The Jehovah's Witnesses placed the comma to support their doctrine.
JWs often assume that if their translation is grammatically possible, it cannot be criticized. More generally, JWs seek to justify the interpretation that fits their doctrine instead of seeking to know the interpretation which best fits the text.
But there is more to interpreting the Bible correctly (or any other text for that matter) than coming up with a grammatically possible translation. In the case of Luke 23:43, there are other considerations which decisively prove the usual translation correct and the NWT rendering wrong. 
So where does the comma belong?
It might seem that there is no way to prove which translation is correct, and that the NWT rendering is a legitimate possibility. However, this is not necessarily true.
It Doesn't Make Any Sense
One of these considerations mentioned above is that placing the comma after 'today' makes it seem that Jesus was emphasizing when He was speaking (i.e. on the day of His crucifixion), which makes absolutely no sense.
Why would Jesus emphasize that He was telling that man today? Of course He was telling Him today. He could not be telling Him yesterday or tomorrow. By definition, any time you tell anyone anything, you are telling them on the day you tell them. How could you not be? It is a frivolous waste of a word, which is especially hard to imagine when Jesus is gasping for breath while slowly dying during a Roman execution. But even if they had been chatting comfortably over dinner, the phrase would have no meaning. One might emphasize that they are telling you today if they were apologizing for not telling you sooner, contrasting it with something they said previously, or emphasizing your need to remember and obey on into the future the thing they are saying this one time. 
The Word "Truly"
Jesus' promise began with the words "Truly, I say to you" translated from the Greek amen soi lego. 
We are used to the word 'amen' being tacked on to the end of a prayer as an expression of concurrence or assent but Jesus used the word a little differently. He put it in front of some of His statements. It was part of His oft used phrase "Truly, I say to you". By leading with this expression Jesus was (obviously) not assenting to anything but was making a strong claim to truth. In other words, He knew firsthand what He was talking about and what He was saying was important. It would be very similar to the Old Testament "Thus says the Lord."
However, what is really significant is the fact that every time Jesus used the expression (over 70 times) the New World Translation either leaves the comma out or puts it immediately after "Truly I say to you". Here are four NWT examples from the book of Luke with plenty more HERE
Truly I say to you, whoever does not receive the Kingdom of God like a young child will by no means enter into it.” (Luke 18:17 NWT)
He said to them: "Truly I say to you, there is no one who has left house or wife or brothers or parents or children for the sake of the Kingdom of God (Luke 18:29 NWT)
and he said: "Truly I say to you that this poor widow put in more than they all did. (Luke 21:3 NWT)
Truly I say to you that this generation will by no means pass away until all things happen. (Luke 21:32 NWT)
Luke 23:43 should be translated just as they were, i.e. the comma immediately after the phrase not after the word 'today' unless there is overwhelming evidence from the context that is somehow different from all the other times Jesus used this expression.
The Word "Paradise" (Greek paradeisos)
Has been used only two other times in the New Testament - in 2 Corinthians 12:4 and Revelation 2:7
And I know how such a man - whether in the body or apart from the body I do not know, God knows — was caught up into Paradise and heard inexpressible words, which a man is not permitted to speak. (2 Corinthians 12:3-4 NASB)
'He who has an ear, let him hear what the Spirit says to the churches. To him who overcomes, I will grant to eat of the tree of life which is in the Paradise of God.' (Revelation 2:7 NASB)
On both occasions there is little doubt that a heavenly realm is being referred to. Nothing in the context indicates otherwise.
Jesus Didn't Go Straight To Paradise.
The Witnesses argue that Jesus could not have promised the thief that they would that very day be together in a heavenly Paradise because when Jesus died, the Bible tells us that He first "descended into the lower parts of the earth". And after His resurrection Jesus told Mary that He had "not yet ascended to the Father" (John 20:17).
This would be true if we were talking about physical locations. Regardless of how how far we go in the universe God's abode is not a place we can actually reach *Nor did Jesus come up with the original version of 'Journey to The Center of The Earth'. The language regarding where Jesus and the thief "went" cannot be understood literally.
* In his book Thy Kingdom Come Charles Taze Russell made the statement that God's governed the universe from a star called Alcyone 
Continue on to Back-Pedaling, Contradictions, and False Prophecy HERE
 The Watchtower. Refashioning the Soul. https://wol.jw.org/en/wol/d/r1/lp-e/2000401?q=soul+sleep&p=par
 Do You Have an Immortal Soul? https://www.jw.org/en/library/magazines/w20070715/Do-You-Have-an-Immortal-Soul/
 Refashioning the Soul. https://wol.jw.org/en/wol/d/r1/lp-e/2000401?q=soul+sleep&p=par
 What Do the Scriptures Say About "Survival After Death"? - Part 1. Heading: What The Human Soul Is.
 Norman Geisler Hell/Part 2. Norman Geisler. The John Ankerberg Show.
 Robert M. Bowman, Jr. Jehovah's Witnesses and Luke 23:43. A Case Study in Watchtower Interpretation.
 Luke Wayne. Does Jesus' Promise to the Criminal in Luke 23:43 indicate that humans have an enduring soul?
 Charles Russell. Thy Kingdom Come. Pg 326