If you debate theists very often, there will soon come a point where you'll start hearing the same arguments over and over again. And although I do my best to bear in mind Greta Christina's wise words on patience and remember that most proselytizers have never been exposed to an effective atheist critique, some of these claims annoy me more than others. Usually, this is because the logic behind them is so patently flawed, or the fallacies so obvious, that even an evangelist with no formal education in critical thinking ought to be able to spot them.
In this post, I'll list a few of the apologetics used by Christian proselytizers that I find the most irritating, in the doubtless vain hope that it will help put them to bed sooner.
Jesus defied chance by fulfilling the messianic prophecies of the Old Testament.
Christian apologists love to tout the many prophecies of the Jewish scriptures and the allegedly staggering odds against anyone fulfilling them by chance. Here's a typically overblown example:
"Someone did the math and figured out that the probability of just eight prophecies being fulfilled [by chance] is one chance in one hundred million billion. That number is millions of times greater than the total number of people who've ever walked the planet!" (Louis Lapides, in Lee Strobel's The Case for Christ, p.246)
Discounting these ludicrous numbers and the fanciful assumptions that doubtless went into them, what these apologists always ignore is that this was not a blind comparison; the Old Testament was not a set of sealed scrolls that was cracked open only after the New Testament was written. No, as even the most hardened apologists acknowledge, the New Testament authors were well-versed in the Old Testament and could well have had the scrolls in front of them while writing.
If they noticed that their story did not fit the guidelines of prophecy, there would have been nothing at all to prevent them from revising, embellishing, or outright inventing, as necessary, to make it conform to the predetermined Old Testament prophecies which any plausible messiah candidate would have to have fulfilled. (This need not imply a deliberate effort to deceive. It may be that they believed Jesus was the messiah so strongly, they assumed that he must have fulfilled the prophecies, even if they didn't have direct knowledge of him doing so.) And once we admit this possibility, those supposedly astronomical odds evaporate.
The gospels must be true stories because they contain references to real people and places.
Apologists such as Lee Strobel make hay out of the fact that some people and places mentioned in the gospels, such as Quirinius or the Jewish bath at Bethesda, did exist in history. They're not reluctant to imply that the gospels' accuracy about these historical facts should convince us to trust them about matters that aren't as easy to verify.
But this doesn't prove that the storyline of the gospels actually happened. At best, it means that the gospels were written by authors who knew of those people and places, but what does that prove? As in the last point, there's nothing to prevent an author from writing a work of fiction that's set against the backdrop of real historical events. If the apologist logic was correct, we'd have to conclude that Indiana Jones and the Last Crusade is an accurate historical documentary, since it, too, depicts real personages (i.e., Adolf Hitler) and places from history.
The New Testament is trustworthy because Jesus' resurrection was vouched for by four hundred witnesses.
This one is particularly irritating because of its willful disregard for the laws of evidence. We do not have four hundred separate, notarized eyewitness accounts of anything in the New Testament. What we have is one verse in the New Testament, by one writer, who says that four hundred people saw the resurrected Jesus.
Clearly, this is a completely different situation. We don't have four hundred separate testimonies that can be checked against each other for consistency, to see if their authors all had the same experience. We don't know who these alleged four hundred witnesses were - neither their names, nor anything else about them by which we could verify their trustworthiness. We don't even know if there actually were four hundred of them, or if Paul might have been fudging the numbers, exaggerating, or honestly miscounting.
If I said, "A thousand people saw me levitate off the ground", that by itself would not establish that I had a thousand witnesses to vouch for my supernatural powers. This kind of evidence is called hearsay, and it's banned from criminal courts for a reason. A witness who can't or won't speak for themself is no witness at all.
Jesus was neither a liar nor a lunatic and therefore must be who he said he was.
This argument, the so-called "Lord/Liar/Lunatic" trilemma usually credited to C.S. Lewis, may be the most absurd of the bunch. It implicitly assumes that the New Testament is historically reliable and that everything in it can be treated as true. Well, if you accept those presuppositions, it hardly matters what Jesus said - the stories of him calming storms, walking on water, healing the sick and raising the dead would be more than sufficient evidence of his divinity.
But if you don't accept that absurdly broad premise, then the trilemma grows another option: lord, liar, lunatic or legend. It's possible that he was a real person, maybe even a would-be religious reformer, but that his words and his deeds became exaggerated over time, or that episodes which would cast doubt on his character have been censored from the historical record. It's also possible that he began as a purely legendary figure who was gradually historicized into a real human being. In any of these cases, the simplistic choices of the trilemma fall apart.