Dan DeWitt has written an excellent article titled “Atheism and the Problem of Evil.” It should be read by anyone who has ever wrestled with the question of evil and the existence of God (which all Christians should).
Here is how he introduces his article:
The biblical explanation of the cosmos is a theme emphasized in the opening verses of Genesis, where each day of creation is stamped with the words “it was good.” But can an unguided world governed by mere chance, as the atheistic worldview suggests, provide any sort of objective foundation or absolute definition of “good”?
If the world is a product of chance, is governed by nothing, and is heading nowhere, then how can we point to some overarching value of goodness? As the prominent atheistic ethicist Kai Nielsen once said, “We have not been able to show that reason requires the moral point of view. . . . Pure practical reason, even with a good knowledge of the facts, will not take you to morality.”  And if we cannot get to the moral point of view from a purely scientific perspective, then how can an atheist use a moral point of view to reject the existence of God?
The Christian isn’t the only one who has to account for the existence of evil; so does the atheist. But how can they?
You can read DeWitt’s article here.