If You Can't Think of a Reason Why God Allows Evil then...
If God has a good reason for allowing evil to exist, should you expect to know what that reason is? There are four main responses to this question. First, some theists answer the question affirmatively and claim to know why God allows evil. Other people suggest possible reasons God might have but don’t claim to be certain of them. Third, there are those who don't have any idea why God allows evil but they still trust there is a good reason. And lastly, many atheists are certain that there is no good reason.
The assumption that many atheists make is that if they cannot think of any good reason, then there must not be a good reason. But is that the most rational option? Should atheists expect to be able to think of every possible reason that God might have? Is it possible that they have not considered all the options? Is it even possible that God has a good reason which no one has ever considered? Perhaps atheists are too quick to jump to this conclusion. Pastor Tim Keller highlights this issue in a talk he gave at Google. He points out that when someone says he can't believe in God because of evil and suffering, he is indirectly claiming to have considered all the possible answers and found them wanting.
When someone says, 'I can't believe in God because he allows such evil and suffering', what you actually are saying is this: 'Because I can't think of any good reason why God would allow evil and suffering, therefore there can't be any good reason'... See the only way to walk away from God is to assume there can't be a good reason.
After appreciating this point, you may be interested in exploring possible reasons as to why God allows evil. If that's you, check out the second half of the video below.
Short Blog: Irony Behind Rejecting God Because of Evil
Video (below): Reconciling a Good God with the Reality of Evil - Woodside Bible Fellowship
Talks at Google, "Making Sense of God: An Invitation to the Skeptical | Tim Keller | Talks at Google," October 19, 2016, YouTube video, 57:53, https://youtu.be/4uIvOniW8xA.
Timestamp: 21:32 - 21:58