Why Do People Refuse to Believe in Evolution?

As we approach the 200th anniversary of the birth of one of the 19th century's most influential scientist, it seems that the percentage of people in the developed world (particularly the US) do not believe in evolution in spite of the overwhelming evidence in favor it. I am NOT saying that the only scientists who do not accept evolution as fact are pseudo-scientific shills paid by institutions like the Discovery Institute, nor do I agree with the religiously anti-religious (Dawkins, Dennett, Harris and Hitchens) who crusade against all forms of religion, and think that one cannot possibly believe in (a) god and accept evolution as true, but I do not understand why so many people of faith refuse to accept evolution (and by extension, plate tectonics, the age of the Earth) as, if not true, than darn close to being true.