Indoctrination. Anyone who's attended public school has been fed the lie over and over again from a very early age. I remember when I was a young Christian and thought to myself, "if the bible is true, how do Adam and Eve fit in with dinosaurs and an earth that's billions of years old?". Obviously the only thing that makes sense is that the earth is young and that dinosaurs coexisted with man prior to Noah's flood.

I had to finally let go of what I was taught all those years. Low and behold as I continued to grow as a Christian I learned how Jesus Christ Himself affirmed a young earth. He's God. He cannot lie, nor be wrong, therefore you can take a young earth to the bank. Now that's just the age of the earth, but evolution hinges on the same indoctrination because it needs the magic ingredient of time to make the theory sound believable.