I have met Christians who insist reason has nothing to do with faith. They seem to think rational world views are all against faith. They say that by your actions and faithfulness and superior virtue you can convince others of the truth of what you believe. Reasoning has little or no place in a Christian’s life.
But someone else thinks some other religion is true. He just “knows”. Perhaps his actions and faithfulness and superior virtue are just as good as any Christian’s. I have met atheists who claimed this. And others of various religions. You are at a standoff. How do you prove Christianity is true?
According to William Lane Craig you can proceed on considerations that are common to both parties.
Rational Self Evidence.
Common Modes of Reasoning.
These three things can be used to demonstrate the Christian’s belief is true and his friend’s beliefs are false. If the Christian can do that then he is in a better position to show that his “epistemic” belief is more rational and thus closer to the truth. Basically “apologetics” has entered the picture, or so claims William Lane Craig.
Apologetics is about sound and persuasive arguments for Christian truth claims. This is why apologetics is worth studying. It is not sufficient to merely claim you have an inner knowledge or experience that demonstrates truth to you. You need to know why your claims are true and be able to demonstrate them to others.