See this below from Eugene Peterson. ( Related: see also my "Occasional Atheist; Coffee, Not Jesus" and "I am in sin if I avoid the appearance of evil"):
The atheist is not always the enemy. Atheists can be among a Christian’s best friends. Atheists, for instance, whose atheism develops out of protest: angry about what is wrong with the world, they are roused to passionate defiance. That a good God permits the birth of crippled children, that a loving God allows rape and torture, that a sovereign God stands aside while the murderous regime of a Genghis Khan or an Adolf Hitler runs its course—such outrageous paradoxes simply cannot be countenanced. So God is eliminated. The removal of God does not reduce the suffering, but it does wipe out the paradox. Such atheism is not the result of logical (or illogical) thought; it is sheer protest. Anger over the suffering and unfairness in the world becomes anger against the God who permits it. Defiance is expressed by denial. Such atheism is commonly full of compassion. It suffers and rages. It is deeply spiritual, in touch with the human condition and eternal values.
Ivan Karamazov is the most famous literary presentation of this atheism of passionate protest
He carried around a notebook in which he copied down every instance of innocent suffering that he had heard or read of. There were terrible things in his notebook:accidents and torture, cruelty and agony, malignity and despair. He specialized in the suffering of innocent children. The accumulated anecdotes served up an unanswerable indictment against the existence of God. But he was always talking about the God in whom he did not believe. He was haunted by the Christ that he rejected.
His very atheism was a grappling with the holy; with love, with meaning. His atheism had far more spiritual depth than the conventional pietism of people who burn incense to mask the world's stink of suffering and cheerfully sing tunes about the sunshine of God..
..Pastors encounter [a] kind of atheism fairly often. My response is to probe further. I ask, "Tell me about this God you don't believe in. What is he like?' After listening to what follows, I can usually agree: "I don't believe in that God either. Given the material the way you present it, I also am an atheist."
-Eugene Peterson, Earth & Altar: The Community of Prayer in a Self-Bound Society, pp. 107-8.
Later refashioned as Where Your Treasure Is: Psalms that Summon You from Self to Community