It has caused a lot of suffering, but that suffering has, in turn, also brought about a lot of good under God's direction. Sure it is, but you couldn't forgive him if he hadn't done something bad against you. I'm not saying that we should do evil so that the good of forgiveness could come about. I'm showing that it's not a contradiction to claim that good can come out of evil. It's not good to promote evil itself, but one of the things about God is that He's capable of taking a bad thing and making good come out of it.
Mercy is one example of that.
Without sin there would be no mercy. These are all virtues that cannot be experienced in a world with no sin and evil. And my response is that the only One who could ever know that is God. You and I couldn't know that because our perspective is too limited. Only God is in a position to accurately answer that question.