Those Christians who reject the biblical timescale or who embrace evolution often defend their position using the two-book fallacy.
Why are Christians so reluctant to accept Genesis as written?
A thorough knowledge of logic can be immensely helpful in our own reasoning, or when reasoning with others. But in addition to any pragmatic advantage, we have a moral obligation to be logical. Thinking rightly is not optional for the Christian. It is something God requires of us.
Christians have a tendency to use certain “religious” terms that are either directly from Scripture, or which are used as shorthand to describe a biblical principle (such as the ‘Trinity’). There is nothing wrong with this. However, it can be a problem in communicating with unbelievers.
Why defend Genesis when so many people don’t even believe in Jesus? Why not concentrate on defending the big issues, like the Gospel and the deity of Christ? Considering all the problems we have in society, should we really be focused on apologetics, rather than trying to change our culture? It takes time and effort to learn to defend biblical creation. Wouldn’t that time be better spent defending the important Christian doctrines, and fighting abortion, “gay marriage”, racism, and other social ills?
Christians rightly recognize the Gospel as an essential Christian doctrine. This vital principle has its roots in the literal history of Genesis. Unfortunately, some professing Christians mishandle Genesis. They interpret its message in an unnatural way to accommodate secular beliefs about origins such as “millions of years” or particles-to-people evolution. These compromised views reduce the Gospel to incoherent nonsense.