Many have used the existence of evil in the world to try to argue that an all-powerful, all-good God does not exist. The line of reasoning usually goes something like this:
1. If there is an all-powerful and all-good God then no evil exists.
2. Evil exists.
3. Therefore an all-powerful and wholly good God does not exist.
Sometimes another conclusion is added:
4. If a God does exist that allows evil, he would not be worthy of worship.
Few people will actually deny premise 2. Although such atheists as Richard Dawkins tell us that the universe has no evil nor good, they turn right around and call religion evil. The focus is instead on premise one, arguing that an all-powerful and all-good God would not allow evil such as we witness regularly in the world. The practical, everyday conclusion by many is:
1a. Since evil exists, God must not exist.
The driver behind such arguments is premise 1. I maintain, however, that this argument is primarily an emotional one and not a logical one. Most of those who believe it do so either because they have personal pain due to some evil act or because they are looking for an excuse to avoid answering to a holy God about their moral life. I maintain that 3, 4, and 1a are not held due to logical conclusions drawn from 1 and 2, for if people were looking at it with pure unemotional logic, the argument fails.
All that is necessary to show the logical failure is to demonstrate that premise 1 is false. By itself, 1 is an argument with a conclusion which holds that a good God would never allow any evil for any reason at any time. Further, the evil we are speaking about is what we, in our opinion, consider evil.
To defeat this argument from evil, we merely have to show the possibility that God might allow evil or can allow evil and still be all-powerful and all-good. Demonstrating this is straightforward.
First, the argument speaks nothing of the moral need for a greater good. It is better that bravery and courage exist than if they do not, but bravery and courage cannot exist except in situations that require them. Ditto for all other attributes requiring self-sacrifice. If there were no painful circumstances, away go heroism, nerve, tenacity, all Herculean achievements and fortitude, they all are eliminated when we bring in an idyllic world where there are no circumstances that require such things. It is difficult to even imagine what such a world would look like. It would be some sort of saccharine-sweet place where no one ever is allowed to smash their thumb with a hammer or get angry at the bratty neighbor kid.
Thus not only is it better that God allow situations requiring bravery and courage, but God is morally obligated to do so, for if He did not, he would be guilty of not being all-good. If God were to somehow create such a world that had no daunting circumstances, He would not be creating a good world, for any good world would have the best things, such as heroes and founders of orphanages.
Second, it might be the case that an all-wise God sees a greater purpose for allowing individuals to experience evil. When a mother takes away the baby’s candy and insists it eat vegetables, the child thinks it to be the end of the world, and no amount of reasoning will convince the child otherwise. Surely we see the benefits of the mother doing such things, and would not call her good if she did not cause the pain in the child. So what good could come of evil? If we avoid the emotional appeals and only look at it logically, we must at least admit this possibility, for surely we do not claim that we are all-wise.
Third, to determine that evil exists in premise 2 requires the existence of a standard of good and evil that we can measure all events in the world. Therefore this standard must be outside of the events in the world, and is a major premise in the moral argument for the existence of God, which goes like this:
A) A universal moral law exists.
B) Universal moral laws require a universal moral lawgiver.
C) A universal moral lawgiver exists. This we commonly call God.
Therefore if premise 2 is valid, then the major premise for moral argument for God, A), is true.
Merely saying something like “I see no purpose for this evil” or “How could a good God have a purpose that evil?” or appealing to other emotional arguments do not refute this line of reasoning, for we are neither all-good, all-wise, nor all-knowing, and those things we do know can find a purpose for some evil, therefore the original syllogism is false. I therefore submit that most critics who bring up the problem of evil as a case against God do so on emotional grounds, not logical ones.
For a more detailed explanation of why the current world is the best one God could have created, see here.