Also See Section I... Choose Life That You Might Live
What is truly interesting is that most people seem to be prejudiced against the Bible, but well disposed towards other 'scriptures'. This is a rather illogical situation, because there is far more evidence in favor of the Bible being true, than there is for any of the other 'holy books'. This includes scientific, historical and archaeological corroboration and the many fulfilled prophecies.
Atheist Anthony Flew has said that the "onus of proof must lie upon the theist."  Unless compelling reasons for Godís existence can be given, there is the "presumption of atheism." Another atheist, Michael Scriven, considers the lack of evidence for Godís existence and the lack of evidence for Santa Claus on the same level.  However, the presumption of atheism actually turns out to be presumptuousness. The Christian must remember that the atheist also shares the burden of proof, which I will attempt to demonstrate below.
First, even if the theist could not muster good arguments for Godís existence, atheism still would not be shown to be true.  The outspoken atheist Kai Nielsen recognizes this: "To show that an argument is invalid or unsound is not to show that the conclusion of the argument is false.... All the proofs of Godís existence may fail, but it still may be the case that God exists." 
Second, the "presumption of atheism" demonstrates a rigging of the rules of philosophical debate in order to play into the hands of the atheist, who himself makes a truth claim. Alvin Plantinga correctly argues that the atheist does not treat the statements "God exists" and "God does not exist" in the same manner.5 The atheist assumes that if one has no evidence for Godís existence, then one is obligated to believe that God does not exist ó whether or not one has evidence against Godís existence. What the atheist fails to see is that atheism is just as much a claim to know something ("God does not exist") as theism ("God exists"). Therefore, the atheistís denial of Godís existence needs just as much substantiation as does the theistís claim; the atheist must give plausible reasons for rejecting Godís existence.
Third, in the absence of evidence for Godís existence, agnosticism, not atheism, is the logical presumption. Even if arguments for Godís existence do not persuade, atheism should not be presumed because atheism is not neutral; pure agnosticism is. Atheism is justified only if there is sufficient evidence against Godís existence.
Fourth, to place belief in Santa Claus or mermaids and belief in God on the same level is mistaken. The issue is not that we have no good evidence for these mythical entities; rather, we have strong evidence that they do not exist. Absence of evidence is not at all the same as evidence of absence, which some atheists fail to see.
Moreover, the theist can muster credible reasons for belief in God. For example, one can argue that the contingency of the universe ó in light of Big Bang cosmology, the expanding universe, and the second law of thermodynamics (which implies that the universe has been "wound up" and will eventually die a heat death) ó demonstrates that the cosmos has not always been here. It could not have popped into existence uncaused, out of absolutely nothing, because we know that whatever begins to exist has a cause. A powerful First Cause like the God of theism plausibly answers the question of the universeís origin. Also, the fine-tunedness of the universe ó with complexly balanced conditions that seem tailored for life ó points to the existence of an intelligent Designer. [See Anthropic Principles]
The existence of objective morality provides further evidence for belief in God. If widow-burning or genocide is really wrong and not just cultural, then it is difficult to account for this universally binding morality, with its sense of "oughtness," on strictly naturalistic terms. (Most people can be convinced that the difference between Adolf Hitler and Mother Teresa is not simply cultural.) These and other reasons demonstrate that the believer is being quite rational ó not presumptuous ó in embracing belief in God.
Paul Copan is a Ph. D. candidate in philosophy at Marquette University and editor of the forthcoming Who Was Jesus? A Jewish-Christian Discussion (Word, 1997).
 Antony Flew, The Presumption of Atheism (London: Pemberton, 1976), 14.
 Michael Scriven, Primary Philosophy (New York: McGraw-Hill, 1966), 103.
 It is important to remember that we are trying to give arguments or good reasons for Godís existence ó not "proofs," which imply a mathematical certainty. All too often the atheistís criteria of acceptability are unreasonably high. One who is genuinely seeking plausible reasons to believe in God can certainly find them.
 Kai Nielsen, Reason and Practice (New York: Harper & Row, 1971), 143-44.
 Alvin Plantinga, "Reason and Belief in God," in Alvin Plantinga and Nicholas Wolterstorff, eds., Faith and Rationality (Notre Dame: University of Notre Dame Press, 1983), 27