When did this happen? Aren't there two contradictory versions of Creation? Isn't it true that the four Gospels, supposed to be the teaching of four men who actually walked with Jesus, don't agree on so many things?
In truth, the Bible was pulled together by various factions of Christianity from numerous competing beliefs. Those which most supported the powers-that-were remained in the Bible. Those which did not were not only excised but ordered destroyed, to reduce the possiblitly of people thinking there might be other paths to heaven.