How about some Keller referencing Lewis:
"My argument against God was that the universe seemed so cruel and unjust. But how had I got this idea of “just” and unjust”?…What was I comparing this universe with when I called it unjust?…Of course I could have given up my idea of justice by saying it was nothing but a private idea of my own. But if I did that, then my argument against God collapsed too—for the argument depended on saying that the world was really unjust, not simply that it did not happen to please my private fancies…. Consequently atheism turns out to be too simple. Lewis recognized that modern objections to God are based on a sense of fair play and justice. People, we believe, ought not to suffer, be excluded, die of hunger or oppression. But the evolutionary mechanism of natural selection depends on death, destruction, and violence of the strong against the weak—these things are all perfectly natural. On what basis, then, does the atheist judge the natural world to be horribly wrong, unfair, and unjust? The nonbeliever in God doesn’t have a good basis for being outraged at injustice, which, as Lewis points out, was the reason for objecting to God in the first place. If you are sure that this natural world is unjust and filled with evil, you are assuming the reality of some extra-natural (or supernatural) standard by which to make your judgment."
