Understanding God’s Justice and His hatred of the wicked?

A few questions…The… question is about God's hatred, his abhorrence of the wicked. What exactly does this term mean? In Deuteronomy 28, God says He will rejoice in destroying the people that forsakes His ways. In other places, he talks about laughing at the wicked as their plans come to naught (I suppose as He precipitates them down to Hell). The Old Testament treats often of the destruction promised evil-doers. The Psalmist sometimes asks for the destruction of his enemies. How am I supposed to reconcile all of this with a loving God? I know Jesus suffered and died for us all, good and wicked, but I am beginning to rethink how I see his teachings, His Passion, and his death.

My understanding of the matter is that God hardens hearts. In one passage, He says you have before you fire and water, whichever you choose shall be given you. In other words, if I forcefully and constantly choose to be a hedonist, God won't spend my whole life preventing me from being a hedonist; he will abandon me to those false pleasures which have become my god. St. Alphonsus, in "Preparation for Death," talks of the way God withdraws His grace from the impenitent and leaves them almost completely unable to repent, easy prey for demons at the hour of death. These to me are examples of God's hatred: if you resolutely choose to contradict Him, He will largely abandon you to your way… How would you have me understand God's hatred? Also I would like to hear your interpretation of the words toward the end of Psalm 138: Have I not hated them who hated thee, O Lord? With a perfect hatred I have hated them and they have become an enemy to me. Is this the passage Jesus was talking about when he taught you have heard it said that you shall love your neighbor and hate your enemy, but amen, I say to you, love your enemies and do good to those who hate you? What does this passage (about perfect hatred) mean?

Why does God seem to change His teaching in this matter?... As always, thanks for the materials; they are eye-opening and educational. Thanks also for the counsel. Jason B.