It is certainly not necessary to think that the six days spoken of in that first chapter of the Bible are intended to be six days of 24 hours each. We may think of them rather as very long periods of time."
These are not the words of a progressive Christian, desperately trying to make room for evolution in his biblical worldview. No, this comes from the pen of the famous opponent of liberalism, J. Gresham Machen. Writing in 1937, he was not alone among the conservatives who vigorously contended with liberalism. The great apologist of biblical inerrancy, B. B. Warfield, said much the same thing decades earlier: "I do not think that there is any general statement in the Bible or any part of the account of creation, either as given in Genesis 1 and 2 or elsewhere alluded to, that need be opposed to evolution." While he rejected naturalistic evolution, he did believe that evolution was one method God used (along with creation-out-of-nothing and "mediate creation," a combination of creation and natural process).
However, for many Christians today, denying the literal reading of Genesis 1 would be to deny inerrancy and open the door to heterodoxy. How did we get to this point?
Quarrel about Relatives
Before Jesus was "conceived by the Holy Spirit," Aristotle, Plato, Ptolemy, and Galen had written wise treatises on scientific questions. As these books entered medieval Europe, Christian scholars recognized their genius in treating science. While they spotted some theological landmines (e.g., Aristotle argued for the eternity of the world and had no room for divine providence), these scholars argued vigorously for the classical sciences. Roger Bacon, the outstanding scientist of the 1200s, borrowed a theme from Augustine when he said ...