Does God Cause Evil?
It is important to begin by defining what we mean by evil if we are going to understand it.
Whether something is evil depends on the nature of the one who experiences it. If a human was born without eyes, we might think that is evil because it is the nature of humans to have eyes. If a stone does not have eyes, we do not think that is evil because sight is not the nature of a stone.
When God created Adam and Eve, Genesis 1:27,31 says, "God created man in his image; in the divine image he created him; male and female he created them... God looked at everything he had made, and he found it very good." The nature of humans changed after Adam and Eve sinned. As Genesis 2:17-19 says, "To the man [Adam] he [God] said: "Because you listened to your wife and ate from the tree of which I had forbidden you to eat, "Cursed be the ground because of you! In toil shall you eat its yield all the days of your life. Thorns and thistles shall it bring forth to you, as you eat of the plants of the field. By the sweat of your face shall you get bread to eat, Until you return to the ground, from which you were taken; For you are dirt, and to dirt you shall return." After the fall, humans inherited a weakened, vulnerable body.
If sickness, pain and death became part of our human nature because of the fall, then it is not evil if we lose our health. It is to be expected. If we never had sickness, pain and death, it would be abnormal. It would be as strange as a chair having eyes. Sickness is an absence of health, not the act of a vindictive God.
According to St. Thomas Aquinas, evil is also not a thing, but instead it is an absence of good. Since it is not a thing, it cannot be created. An analogy to this is a shadow. No one can create a shadow, because it is an absence of light. One can cast a shadow by blocking a light, but it is not a thing.
Things cannot, of themselves, be evil. God can make a tree that has the ability to oxidize and thus burn. But God does not light the fire. The fire can be either a good thing or a harmful thing, depending on how it is used. Fire can heat us on a cold day or cook our food. It can also burn down a building and kill people. So it is not the fire itself that is evil. What can be evil is the reason, or the will, of the person who starts the fire. The US Court system recognizes this intention as a factor in whether something is a crime or an accident. A person that is insane, severely mentally retarded, or acting in self-defense is treated differently than one who commits a premeditated act. A person who burns a building may be doing a good thing if it is a storage facility for the enemy’s weapons, because that would protect others.
The story of Adam and Eve shows that God created humans with free will. We can choose to do good or we can sin. We can obey or disobey God. For a sin to be mortal, it must be grave matter, we must be capable of knowing and know it is a grave matter, and of our free will decide to do it anyway. It is the nature of humans to go either way.
Can God do evil?
We can observe from experience that some things are better than others. There is a continuum that ranges from an absence of good, to better, to best, the ultimate goodness. As humans, we neither have an absence of good or ultimate goodness, since we are capable of sin.
If we define the nature of God as having the ultimate goodness, then it is not possible for God to will evil. Why? Doing evil would cause an absence of goodness. To use an analogy, if I put ice in a pot of boiling water, it would not be boiling water until it again reached the temperature of 212 degrees Fahrenheit. With the absence of heat, it would lose its boiling nature. It would not be at the ultimately highest temperature that water can be. In the same way, if you mix a will to do evil with the ultimate goodness of God, God would lose his ultimate goodness and, therefore, would not be God. The nature of this being would be the same as humans.
Is evil, then, caused by God lacking the power to stop it? There are some things God can't do. He can't make a square circle. We have to trust that God made us according to his loving plan. He gave us free will, because we would be like puppets if we did not have it. He can't make us have both free will and not able to choose to do evil. Also, he could not let the sin of Adam and Eve go unpunished, because God is totally just. Despite our sinful choices, God makes it possible to turn evil to good. We do this by uniting our sufferings with the sufferings of Christ for the redemption of the world.
It is not evil for God to remove his grace from us when we sin. He warned us what would happen if we die in unrepented mortal sin. He is merely giving us what he promised he would. God wills the salvation of all. He gives us all the grace we need to be holy. By our Baptism, we are given an inheritance of eternal life. We don't have to earn it, because it is a free gift. Yet we can choose to lose it through serious sin. Ultimately, the responsibility for obeying God is ours.
To summarize, evil:
- depends on nature,
- it is not a thing,
- it cannot be created,
- is caused by our free will to sin
- is not the will of God, so therefore, God cannot cause evil.
- God does not cause sickness, pain or death.