Most Christian apologists to whom I have been exposed state that the best argument against Christianity is the Problem of Evil: "The epistemic question posed by evil is whether the world contains undesirable states of affairs that provide the basis for an argument that makes it unreasonable to believe in the existence of God." The counter to this rebuttal to Christianity is usually Skeptical Theism: "Skeptical theism is a strategy for bringing human cognitive limitations to bear in reply to arguments from evil against the existence of God." (i.e. "How do you know that God doesn't have a greater purpose for the evil?")
Click on the link below for a podcast rejecting this apologetic:
