We should not think much today about what he did on Earth, no matter how awful we believe his actions and attitudes to be. What we need to do today is pray for him, even if that's something he would, were he still here, to scoff about. We should do that because no matter what he said or did, he was still a human being, and human dignity requires that we have regard for his soul. Even, and perhaps especially, if we believe him evil. Every single human life should mean that much.
This is an excellent opportunity for those who preach tolerance to demonstrate it. This is the chance to show that we respect him as a person even though we found his ways in life reprehensible and irresponsible. Forget how he lived and say a prayer for him. Isn't that what we really want, redemption for everyone, for every man woman and child to be made better, to become more fully and completely human? It's what we should want if we don't.
You may have noticed that the Catholics, while routinely declaring people to be in Heaven, have not once formally declared a person to be in Hell. That's at the crux of their teaching to hate the sin and love the sinner; we don't know, we cannot know, how morally culpable any given person was or is for their actions. We may rightfully condemn the act. We can never condemn the person.
Judge not lest ye be judged. Do not judge Fred Phelps; have mercy upon him even if you're certain he would afford none to you. How he acted towards you is not on you. How you act towards him, despite him, is.