One common, and understandable, objection to the existence of the God of the Bible is the reality of evil. It’s not just an intellectual issue; it’s a very personal and deeply emotional one. But a number of considerations can help us see that the existence of God and the existence of evil in our world are compatible and even necessary.
(1) One interesting point is this: In order for evil to be a problem for God, we must have an adequate basis for considering something genuinely “evil.” But if God does not exist, what is the basis for calling anything "evil"? If all that exists is mere physical matter, we might experience pain and suffering, but how could that rightly be considered evil? The irony is that the “problem of evil” is typically understood as a unique dilemma for believers in God, but it turns out that it’s also a major problem for those who reject God. To be sure, the reality of evil is a problem for God-believers. But Naturalism (having no God) cannot justify the existence of evil that poses the problem in the first place. In that sense, the challenge for Christians is to give an adequate answer to the problem, while the even bigger challenge for the Naturalist is to give an adequate explanation of why there is a problem to begin with. Furthermore, without God, there simply is no answer to pain and suffering. That's just the way it is. We can't make sense of it now and we have no hope for anything different in the future.
(2) If there is a God, it makes sense that God could have created a world with no evil. For instance, He might have created a universe with no life, or He might have created a world with robotic creatures that are programmed to love him and only act in morally right ways. But what sense does it make to say that one can be “programmed to love” or be “made to act only morally”? Love and moral accountability seem to require significant human freedom. Otherwise, it’s not really “love” and it’s not really “moral” action.
If God wanted creatures that could truly love and be morally accountable, it appears necessary that he would grant human freedom. But if we are truly free, then it also makes sense to think that even God could not guarantee that we would not use that freedom to generate evil and all kinds of suffering and pain for ourselves and others. This is sometimes referred to as the “free will” defense. This consideration suggests that God had good reason for creating us as he did (with freedom), even if that resulted in the eventual existence of evil in our world.
(3) While the “free will” defense may help to explain much of the evil in the world that comes from human decisions to kill, rob, destroy, abuse, etc., it’s not clear how this explains much of the “natural evil” in our world—earthquakes, tsunamis, volcanoes, hurricanes, tornados, cancer, etc. We could say that such natural evils all stemmed from the original sin of the first humans. Yet, while there may be some theological merit in this (see Genesis 3:17-19; Romans 8:20-21), many people cannot recognize a sufficient connection.
Natural evils might be better explained by considering the necessity of “natural law” in our universe. The regular and predictable operation of nature does not just make science possible; it also makes moral accountability possible. Moral accountability requires that we be able to predict consequences and make decisions within an orderly context. At the same time, the regularities of nature will unavoidably lead to disaster. Our inclinations might be to demand that God intervene in each case, but then natural law, which is necessary for moral accountability, is eliminated.
(4) Another consideration is sometimes called the “soul-making” idea: While God did not originally intend for evil to exist in our world, he uses evil, pain, and suffering to help us develop desirable virtues like patience, forgiveness, and reliance on Him. When we encounter pain, suffering, and inevitable death, we are forced to face our finiteness. And this can actually lead us to see the need for our own forgiveness from the only One who has an ultimate resolution to our times of anguish.
(5) The considerations above should help us recognize that God’s existence, given his purposes for humanity, is quite compatible with the existence of pain, suffering, and evil. But a more adequate response must emphasize what God has already done about evil. If God were a mere bystander, idly observing our suffering, He could rightly be charged with indifference and viewed with disdain. But the God of the Bible is a God who clearly cares, because He is a God who shares in our suffering. That is the message of Christ, the Son of God. Unlike the religion of Buddhism that emphasizes suffering and seeks escape from it, Christianity stresses that God subjected Himself to suffering in our behalf.
(6) We should also bear in mind what God will do with evil and what he plans to do for us. A central Christian message is that “our present sufferings are not worth comparing with the glory that will be revealed in us” (Romans 8:18). “He [God] who did not spare his own Son, but gave him up for us all—how will he not also, along with him, graciously give us all things” (Romans 8:32). The ultimate deceiver and culprit of evil—the devil—will finally and decisively be destroyed and God will bring a New Heaven and a New Earth without mourning, crying, pain, or death (see Revelation 21-22).