I understand what you are trying to say. No one should live in hate. No one should allow their lives to be controlled by it.
But this is one of those times when I think religious teaching fails us as humans. In this circumstance, we must be outraged as a society. We MUST condemn this evil. We must feel the hate for awhile in order to accomplish these things.
In this circumstance, for someone who loved that child, hate is unavoidable for a time. We are humans full of sin. While we should not revel in our sin, I don't think we ought to be made to feel "less than", or guilty or wrong for being human and having these emotions. Denying them, or insisting that it cannot exist if we are Christians is harmful.
I like your post #44, though I think true religion rightly understood serves us very well. To do less that react as you suggest would be the equivalent of serving two masters, both God and satan. You can’t. You either serve one or the other.
I won’t quote your entire #44. I’ll just say that there’s nothing in it that I disagree with.