Jason Rosenhouse recently blogged Why Creationists Believe as They Do. Here's an excerpt:
"As fundamentalists see it, their confidence in the Bible is the most rational thing in the world. They talk more about facts, logic and evidence than just about anyone else you'll ever meet. It certainly is not the result of blind faith or anything like that."
I think there are two distinct species of creationists (and Christian in general) that need to be examined and explained.
The first type of creationist is the common garden variety which Rosenhouse describes. These are your average churchgoers, your creation science buffs (From personal experience and the experience of others I know it seems that every church is blessed, so to speak, with some guy who has read a ton of creationist material and is known as the local "expert" to be consulted on the matter). These poor dupes are not without all common sense. They know full well that it is inappropriate to believe something that you don't have a good reason to. In sermons, conversations with friends, books they've read, etc. the people that they trust have told them that tons of evidence exists. Miraculous prophecies in the bible were confirmed. Noah's Ark was found. Seashells were found a mountaintop proving the flood of Noah. They assume these people would not lie to them or be grossly mistaken about the matter at hand, after all, it is only natural for us to believe what other people tell us is true. The solution for these people is simply more education, and this is a problem that I think is increasingly shrinking with the advent of the internet and with a great increase in college education. The evidence that I have to support my view here is that most people, I think, start out with a heavy bias toward creationism. But amongst scientists (again, many of whom must have started out as creationists) you won't find very many creationists at all. In fact, far less than 1% of scientists believe in creationism. The same goes for philosophers and theistic belief; over 70% of philosophers "accept or lean towards" atheism. In other words, people who familiarize themselves with the evidence stop believing creationism. Most people are just not perverse enough to act otherwise. That's my story. That's the story of a guy I wrote about the other day. And there is a book review on amazon that confirms more of the same.
The second type of creationist is the evidence-resistant strain. These are the leaders of the movement, like Norman Geisler, William Lane Craig, and Ken Ham. These men are looked to as leaders in the evangelical/creationist movement in part (I think) because they all have some credentials. Ham has a Bachelor's in applied science, Geisler holds a PhD in philosophy, and Craig has more degrees than a thermometer. I expect that anyone who has had a chance to actually look at the evidence concerning the age of the earth and evolution would have to be rigidly dogmatic and not remotely reasonable in order to hold on to the alternative conclusion. It's natural selection; just as the only bacteria who survive an antibiotic are those who have some type of resistance, the only creationists who remain creationists after looking at the evidence are ones who could never be dissuaded by any evidence whatsoever. And just look at what we see: Ham is an extreme relativist and presuppositionalist who claims that the evidence can't be looked at on its own but that one has to choose sides before looking at the evidence and then shoehorn that evidence into the pre-chosen framework (I wouldn't want that guy to serve jury duty-- ever!). William Lane Craig emphasizes that the real reason you should be a Christian is because of the inner witness of the Holy Spirit. Geisler, though he claims to be an evidentialist, is really very superficial in his reasoning (read something he's written and see what I mean) and more or less creates arbitrary and impossible criteria for identifying error in the Bible, as Chris Hallquist beautifully demonstrated in UFOs Ghosts and a Rising God.
The trouble is that your average creationist gets all of his thinking from the dogmatic heroes of creationism, and never hears much of anything else. The leaders of these movements understand very well that a goodly number (if not a majority) of their garden-variety followers likely won't be impressed with simple dogmatism, and this is why they go to the lengths they do to come up with arguments and evidence that will sound really appealing. It doesn't have to stand up to scrutiny; After all, most members of the poor garden variety will never rigorously check the facts being presented (a fact creationist leaders no doubt are aware of). Just as long as whatever you're saying sounds really compelling, you've got 'em. For William Lane Craig, Ken Ham, and Norman Geisler, every argument is just bait to catch more souls for Jesus. They could care less if no evidence supported their view or even whether massive evidence contradicted their view; Ham and Craig have even said as much.
With the advent of greater education and the internet, it is becoming easier and easier to catch these folks in outright lies. They may realize that, which is why we are now witnessing the transitional forms that we are: creationists who want to rely on some sort of non-evidential justification for their beliefs as well as a form of evidence. Craig attempts to make good arguments for God but at the same time emphasizes the inner witness of the holy spirit. Ham goes for presuppositionalism but also does his part to explain away the evidence as representing something else and his site, from time to time, does indeed introduce evidential argumentation. My guess is that eventually this will all result in the evolution of purely philosophical or fideistic defenses of faith with very little, if any, mention of evidence or anything else. And that's the trap the creationists are caught in: I have doubts as to whether anyone, even the less sophisticated and less learned, will find that compelling. This may well lead to the extinction (or near extinction) of the entire creationist movement, and maybe even the extinction (or near extinction) of faith.