If you ask young-earth creationists what they think about postmodernism, you’ll find they generally consider it the height of liberal apostasy. Truth, they’ll tell you, is absolute, and not just some postmodernist “social construct.” If you then point out some of the scientific evidence against a literal Genesis creation, you’ll catch them in a bit of hypocrisy. Everybody has a worldview, they’ll tell you. Theirs is a Christian worldview, and yours is a materialistic worldview, and the same evidence can be used to support either one. In other words, your evidence can’t disprove their creationism.
Whether you call it “postmodernism” or whether you prefer the more verbose “everybody has a worldview,” the result is the same: you’re claiming that it’s impossible to tell what the real truth is by comparing your conclusions to the evidence. Worldview (allegedly) overpowers the evidence, and colors one’s conclusions to the point that all conclusions end up being subjective and irrelevant. That’s postmodernism in a nutshell—the very doctrine the creationists condemn as liberal apostasy. But creationism can’t survive without it.
What the creationist fails to acknowledge is that this is only true for certain types of worldview. A worldview is a system of interpretation, by which you analyze your perceptions, correlate them with your previous perceptions, and draw conclusions consistent with the knowledge you already have. Where different worldviews differ is in the techniques they use for analysis, correlation, and interpretation.
The creationist worldview, for instance, begins by defining what conclusion has to be reached, and then employs various techniques like rationalization, superstition, cherry-picking, quote-mining, and so on, in order to guarantee that the “correct” conclusion is obtained. From the point of view of their own experience, it’s quite true that one cannot tell the relationship between their conclusion and the truth just by looking at the evidence in the context of (their own) worldview.
The scientific worldview, by contrast, does not define its conclusions in advance, and uses a variety of techniques that have repeatedly proven their value in distinguishing truth from error and in detecting and eliminating bias. The scientific worldview is a worldview focused on verification of one’s preliminary conclusions, and disproving them when they are false. That’s a universally useful worldview, which is why there have been many Christians who have also adopted it (as Christians themselves will happily point out).
Thus, the difference between the creationist worldview and the scientific worldview is not that the scientist is pursuing a predetermined conclusion that God does not exist. If that were the case, it would be a great embarrassment to Christians if any famous Christians were also scientists. But it isn’t. Christians are proud of their more scientific members, and that’s because the scientific worldview is so successful in determining real-world truth.
The reason science is so successful is the same as the difference between the scientific worldview and the creationist worldview: verification. Science assumes that human conclusions will be unreliable and incorrect a lot of the time, and therefore it emphasizes techniques for detecting and eliminating errors, and conversely for verifying and reinforcing correct conclusions. The creationist worldview, however, has the opposite focus: creationism emphasizes techniques for denying that Genesis is ever wrong about anything, obscuring the distinction between truth and falsehood, and drawing the same conclusions no matter what shape the evidence takes.
The reason creationists are so opposed to admitting that there are errors in their dogma is that their only source of “truth” is what a bunch of men said thousands of years ago. If that dogma were ever lost or discredited, there is no scientific examination of the real world that would lead to the same set of conclusions. Since the prophets are all dead, that would leave believers with no way to re-establish the validity of their teachings. Hence their mistrust of the scientific worldview, and the anti-verifiability of creationism.
Yes, different people do have different worldviews, but not all worldviews are equally reliable. Well-informed creationists inevitably become postmodernists, insisting that nobody really knows the truth and everybody just follows their own worldview. And that may be true as far as their own personal experience is concerned. But the scientific worldview has learned from the accumulated experience of millennia, and is not only reliable but verifiable. If you want to believe whatever predetermined conclusions you choose, go ahead and embrace an unverifiable worldview, like the postmodernists and creationists. But if you want to know the real-world truth, pick a better worldview.