Justin Katz contrasts intricacies of love and hate from both a Jewish and Christian perspective.
Rabbi Soloveichik states that there is "no minimizing the difference between Judaism and Christianity on whether hate can be virtuous," and the more one considers it, the more the question seems to relate to elemental beliefs. From a Christian point of view, the most profound reality that those who killed Jesus "knew not" was that theirs was an act of deicide. Borrowing a phrase from Jacoby, "those who torture and murder without qualm, who are pitiless in the pain they inflict on others," ignore what is sacred in every human being. In charity, we hope that they know not the spiritual truth of what they do.
That charity, as an expression of love, is critical for our own well-being. In order to hate, no matter how under control we believe the emotion to be, we must also turn our eyes from the sacred in those whom we hate. For hatred’s sake, we deny that, somewhere within them, God is part of their true natures. In doing so, we deny that He is necessarily part of our own.
He also touches on a statement by columnist Jeff Jacoby. Jimmy Akin previously wrote a post Mercy Even For Monsters that also addressed some of these issues.
Here is another interesting treatment in First Things on the same subject by Meir Y. Soloveichik.
