I've heard plenty of Christians try to answer the why question by going back to the what. "You have to believe because Jesus is the Son of God." But that's answering the why with more what. Increasingly we live in a time in which you can't avoid the why question. Just giving the what (for example, a vivid gospel presentation) worked in the days when the cultural institutions created an environment in which Christianity just felt true or at least honorable. But in a post-Christendom society, in the marketplace of ideas, you have to explain why this is true, or people will just dismiss it.
Timothy KellerGod's grace and forgiveness, while free to the recipient, are always costly for the giver. From the earliest parts of the Bible, it was understood that God could not forgive without sacrifice. No one who is seriously wronged can โjust forgiveโ the perpetrator.
Timothy KellerLife in this fallen world is to a great degree meaningless, our aspirations are constantly being frustrated, and sometimes the respectable people are oppressive and bigoted. And yet there is a Good that will triumph over Evil in the end. From a Christian perspective the problem with both kinds of stories is that they tend to blame problems on things besides sin and identify salvation in things besides God โ and therefore are ultimately too simplistic.
Timothy Keller