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 KellerFaith in the gospel restructures our motivations, our self-understanding, our identity, and our view of the world. Behavioral compliance to rules without heart-change will be superficial and fleetingโฆ We can only change permanently as we take the gospel more deeply into our understanding and into our hearts. We must feed on the gospel, as it were, digesting it and making it part of ourselves. That is how we grow.
Timothy KellerJesus Christ doesnโt just give us truths; he is the truth. Jesus Christ is the prophet to end all prophets. He gives us hard-copy words from God, truths on which we can build our lives, truths we have to submit to, truths we have to obey, and truths we have to build our lives on, but he himself is the truth.
Timothy KellerOur character is mainly shaped by our primary social community - the people with whom we eat, play, converse, and study.
Timothy KellerBecause creation was made in the image of a God who is equally one and many, the human race will finally be reunited and our racial and cultural diversity will remain intact in the renewed world. The human race finally lives together in peace and interdependence. Glory to God in the highest goes with peace on earth.
Timothy Keller