When religious people say they oppose evolution it almost always seems like they don't understand what they're disagreeing with. Evolution is just variation and natural selection. Did Noah have many children? Were they different from each other? That's variation. Did some of those children become more successful than others? That's natural selection. Evolution is 100% compatible with the bible.
Even the creationists at the Creation Museum accept speciation via natural selection. So what's the big problem?
The problem is not evolution, but the implications of evolution, some of which are or aren't contradicted by the bible depending on which creationist you're talking with. "Creationists" do not share the same creation myth; the particulars differ between various schools of thought. Brian Dunning's
What Do Creationists Really Believe episode of "Skeptiod" did a good job outlining some of the strategies to reconcile what's in the bible with what the evidence actually shows. Here's the spectrum, in order from "most compatible" to "least compatible".
Old Earth:
- Deism: God is the prime mover of the universe. He created and then left it alone without further interference. God did not create the solar system, Earth, or life on earth specifically, all of which emerged from evolution and other ordinary natural physical processes.
- Theistic Evolution: God chose to create the natural world consistent with the scientific consensus by directing the naturally-appearing and accepted mechanisms of geology, biology, and evolution as his tools. (Catholic Church)
- Evolutionary Creationism: "There was a literal Adam and Eve, the first spiritually aware humans, who happened to come into being the same way that all early humans did." (Denis Lamoureux)
- Progressive Creationism: "The geologic and prehistoric record are accepted, including dinosaurs and other early life forms, but humans and other modern animals were created by God as special events. (There is no evolutionary link between the apes and humans.)"
- Day-Age Creationism: "The six days of the Creation correspond to six scientifically-based epochs in the Earth's history." (Jehovah's Witnesses)
- Gap Creationism: "God created the heavens and the earth, then 4.5 billion years later, Genesis occurred in six literal days." (Jimmy Swaggart)
Young Earth:
- Omphalism: God created the earth with the perfect appearance of being old and natural. Adam and Eve were created with omphalos (bellybuttons), trees were created with rings, light was created in transit between distant galaxies and the earth, etc. The evidence for evolution is all forgeries, but they're forgeries that God made.
- Modern Young Earth Fundamentalism: The literal interpretation of Genesis is the inerrant, literally correct history of the earth. Every theory of modern science that conflicts with the biblical account is incorrect. (Creation Museum)
I think knowing about the different kinds of creationists is important for three reasons.
First, creationists like to paint a situation where science is always changing and can't agree while the bible provides a more consistent picture when it's really quite the opposite. Scientists agree on the general picture: the age of the earth, common descent, and the way that humans fit into natural history. They *do* argue about particulars like whether a particular hominid is a descendant or cousins of another species. It's *creationists* who can't agree on what's true, with some thinking that the earth is 750,000x older than others, some accepting common descent and some not, some accepting macroevolution and some not.
Second, it always seems like a lazy dodge to me when someone says "I'm a religious person so I believe the bible". Fine, you believe the bible. All of it, or just some of the parts? Do you accept those parts literally or figuratively? How do you explain the inconsistency between what you believe and the stuff I can actually take you to and point at? There's a lot more to talk about, even with other rival creationists.
And third, I think it helps science fans to know this stuff. The party line on science education is that you don't need to accept or agree with evolution but you need to understand the concept so that you know what you're disagreeing with. By the same token scientists don't need to agree with creationists, but it really helps communication if you can tell your Deists from your Young Earth Fundamentalists. Conversely, if you really are talking to a Young Earth Fundamentalist, it might help to show how you don't have to completely abandon your faith in order to resolve many of the conflicts between science and a literalist interpreation of religion.
Caveat: the above is a list of major creationist schools of thought, not an exhaustive list of all possible creationists. Hindu and Muslim creationists, Flying Spaghetti Monsterists, and others are not listed, for example.