(from Baker Encyclopedia of Christian Apologetics: Baker, 1999)

If God is absolutely good, then why is there evil? The problem of evil is a serious challenge to the defense of Christianity. Actually there are many problems relating to evil, for example, the problems about its origin, nature, purpose, and avoidability. The problems of evil can be divided among moral, metaphysical, and physical.

Although every worldview has to deal with the problem of evil, it is an especially acute problem for theism. Of the three major worldviews, Atheism affirms the reality of evil and denies the reality of God. Pantheism affirms the reality of God but denies the reality of evil. Theism affirms the reality of both God and evil. Herein is the problem; how can an absolutely good Being (God) be compatible with evil, the opposite of good?

As compared with the other worldviews that affirm both God and evil, theism would seem to be in a more disadvantageous position. Finite godism, for example, can claim that God desires to destroy evil but is unable to because he is limited in power. Deism, likewise, can distance God from evil by stressing that God is not immanent in the world, at least not supernaturally. We are on our own. And for panentheism evil is a necessary part of the ongoing progress of the interaction of God and the world (his body).

The problem for theism is that it not only believes God is all-powerful and could destroy evil, but he is all-loving and should destroy it. Further the theistic God is all-knowing and created this world fully aware of what would happen. What is more, God created the world freely, so that he could have done otherwise.

It is in the context of this kind of theistic God that we approach problems of evil.

Where did evil come from? An absolutely good God cannot create evil. Nor, would it seem, can a perfect creature give rise to imperfection. Whence, then, evil? The problem can be summarized:

However, in a theistic universe these are the only two sources for moral evil. Therefore, there seems to be no solution for the origin of evil in a theistic universe.

The basic elements in the theistic response to this problem are found in Augustine and Thomas Aquinas. Theists since then have followed the contours of their thought. Both agreed on the response that can be stated as follows:

God is good, and he created good creatures with a good power called free will. Unfortunately, they used this good power to bring evil into the universe by rebelling against their Creator. So evil did arise from good, not directly but indirectly, by the abuse of a good power called freedom. Freedom in itself is not evil. It is good to be free. But with freedom comes the possibility of evil. So God is responsible for making evil possible, but free creatures are responsible for making it actual.

Of course, other questions attach to this free choice solution to the origin of evil. One is, what caused the first creature to choose evil?

Theists distinguish between the primary cause of a free action (God) and the secondary cause (a human being). God gave the power of choice. However, God is not responsible for the exercise of that free choice to do evil. God does not perform the free action for us. Human free choice is not a mere instrumental cause through which God works. Human beings are the efficient, albeit secondary, cause of their own free actions. God produces the fact of free choice, but each human performs the act of free choice. God then is responsible for the possibility of evil, but we must bear the responsibility for the actuality of it. God neither wills evil to be done, nor wills it not to be done. He wills to permit evil to be done, and this is good.

But if God cannot will evil, then what is the cause of it? No action can be uncaused, since this violates the first principle of causality that demands that every event has a cause.

To respond to this question it is necessary to unpack the nature of free choice. There are three basic views of the nature of free choice: In determinism, a free act is caused by another; in indeterminism, it is uncaused, and in self-determinism it is caused by oneself. Determinism would eliminate human responsibility, since another caused the action, not ourselves. Indeterminism is irrational, since a fundamental rule of reason is that every action has a cause. It follows, then, that every free choice must be self caused.

Of course, a person uses the power of free choice to make free choices. However, the person is not free choice. He simply has free choice. It is wrong to say I am free choice; I simply have free choice. So, l am the efficient cause of my own free actions, but the power of free choice is the means by which I freely act.

There is another dimension to this difficulty. What is the nature of evil? That is, what is the essence or identity of evil? This too, is a particularly pesky problem for a classical theist. For God alone is eternal, and everything he created was good. What, then, is evil?

Theists reject dualism. Evil is not a coeternal principle outside of God. For not all opposites like good and evil are first principles. This wrongly assumes that just because something can be essentially good (God), something can be essentially bad. But once dualism is rejected, one has great difficulty explaining the reality of evil. If evil is not something outside of God, and it cannot be anything inside of God, then what is it? The problem can be summarized this way.

Rejecting the first premise leads to dualism. Likewise, denying the second leads to illusionism which denies the reality of evil. Neither is acceptable to a theist. What, then, is the solution? To agree that God did not create all things is to deny his sovereignty. To say evil is nothing denies reality. However, to admit that God caused all things and evil is something is to acknowledge that God caused evil—a conclusion rejected by Aquinas. But this conclusion seems to follow logically from these premises. Unless one rejects the truth of one of the premises, he must accept the truth of the conclusion.