[If] we truly want to progress on the path, we must regard our enemies as our best teachers.  For whoever holds love and compassion in high esteem, the practice of tolerance is essential, and it requires an enemy. We must be grateful to our enemies, then, because they help us best engender a serene mind! Anger and hatred are the real enemies that we must confront and defeat, not the “enemies” who appear from time to time in our lives.

The Dalai Lama