A large amount of human suffering is accounted for by its connection with human sin. Whatever so-called physical evil is needed to prevent moral evil, or to punish it, or to cure it, or to discipline in moral good, is not really evil. Any earthly suffering which saves us from sin is to be classed among benefits. There is nothing to perplex either mind or heart in the circumstance that sin causes a profound and widespread unhappiness. It is strange that it should sometimes apparently produce so little misery; only a dull conscience, I think, will be surprised that it produces so much. It is merely in so far as physical evil is dissociated from moral evil that its existence is a problem and a perplexity. But the very existence of moral evil is a most painful mystery. The absence of physical evil while moral evil was present would be inconsistent with a moral government of the world; whereas if moral evil were removed no real difficulty would be left. Physical evil may be a relative good, which God can easily be conceived of as causing and approving; moral evil is an unconditional evil, and cannot be the work of any morally perfect being.
Have we any reason, however, to suppose that sin is willed by God in the sense either of being caused or approved by Him? All the sin we know of on earth is willed by man, and all the sin which Scripture tells us of as existing elsewhere is said to be willed by evil spirits; neither nature nor Scripture informs us that there is any moral evil willed by God. In other words, there are no facts which refer us to God as the author of evil. In the absence of facts, we can, it is true, form conjectures, and give expression to them in such questions as, How could God make beings capable of sinning? Why did He not prevent them sinning? Wherefore has He permitted sin to endure so long and spread so widely? But thoughtful searchers for truth, at least after a certain age, cannot feel much interested in, or much perplexed by, questions like these. They will be quite willing to leave the discussion of them to debating societies. They will resolutely refuse to assign the same value to conjectures as to facts.
Sin is not God's work. Moral order may exist without moral disorder, but moral disorder can only exist as rebellion against moral order. The very notion of moral evil implies a moral good which it contravenes, and a moral law by which it is condemned. It can never be thought of as other than a something grafted on nature, by which nature is perverted and depraved. It is not natural, but unnatural; not primary and original, but secondary and derivative; not the law, but the violation of the law.