Which fundamentals will lead their believers to be the most loving and receptive to those with whom they differ? Which set of unavoidably exclusive beliefs will lead us to humble, peace-loving behaviour?

Why would such an exclusive belief system lead to behaviour that was so open to others? It was because Christians had within their belief system the strongest possible resource for practising sacrificial service, generosity and peace-making. At the very heart of their view of reality was a man who died for his enemies, praying for their forgiveness. Relfection on this could only lead to a radically different way of dealing with those who were different from them. It meant they could not act in violence and oppression toward their opponents.

It is not a religious act that makes the Christian, but participation in the sufferings of God in the secular life. That is metanoia [repenteance]: not in the first place thinking about one's own needs, problems, sins and fears, but allowing oneself to be caught up into the way of Jesus Christ ... Pain is a holy angel. Through him men have become greater than through all the joys of the world ... The pain of longing, which often can be felt physically, must be there, and we shall not and need not talk it away. But it needs to be overcome every time, and thus there is an even holier angel than the one of pain, that is the one of joy in God.

Imagine trying to look directly at the sun in order to learn about it. You can't do it. It will burn out your retinas, ruining your capacity to take it in. A far better way to learn about the existence, power and quality of the sun is to look at the world it shows you, to recognise how it sustains everything you see and enables you to see it.

We should not try to 'look into the sun', as it were, demanding irrefutable proofs for God. Instead we should 'look what the sun shows us.' Which account of the world has the most 'explanatory power' to make sense of what we see in the world and in ourselves? We have a sense that the world is not the way it ought to be. We have a sense that we are very flawed and yet very great. We have a longing for love and beauty that nothing in this world can fulfill. We have a deep need to know meaning and purpose. Which worldview best accounts for these things?

Christians do not claim that their faith gives them omniscience or absolute knowledge of reality. Only God has that. But they believe that the Christian account of things – creation, fall, redemption and restoration – makes the most sense of the world.

If the God of the Bible exists, he is not the man in the attic, but the Playwright. That means we won't be able to find him like we would find a passive object with the powers of empirical investigation. Rather, we must find the clues to his reality that he has written into the universe, including into us. That is why, if God exists, we would expect to find that he appeals to our rational faculties. If we were made 'in his image' as rational, personal beings, there should be some resonance between his mind and ours. It also means that reason alone won't be enough. The Playwright can only be known through personal revelation.

For many years I looked at life like a case at law. It was a series of proofs. When you’re young you prove how brave you are, or smart; then, what a good lover; then, a good father; finally, how wise, or powerful. But underlying it all, I see now, there was a presumption. That one moved...on an upward path towards some elevation, where...I would be justified, or even condemned. A verdict anyway. I think now that my disaster really began I looked up one day...and the bench was empty. No judge in sight. And all that remained was the endless argument with oneself, this pointless litigation of existence before an empty bench...which of course, is another way of saying – despair.

If our highest goal in life is the good of our family, then we will tend to care less for other families. If our highest goal is the good of our nation, tribe or race, then w will tend to be racist or nationalistic. If our ultimate goal in life is our own individual happiness, then we will put our economic and power interests ahead of those of others. Only if God is our summum bonum, our ultimate good and life centre, will we find our heart drawn out not only to people of all families, races and classes, but to the whole world in general.

The Reason for God by Timothy Keller