Now, as a genuine practitioner of compassion and Bodhicitta, you must develop tolerance. And in order to practice sincerely and to develop patience, you need someone who willfully hurts you. Thus, these people give us real opportunities to practice these things. They are testing our inner strength in a way that even our guru cannot. Even the Buddha possesses no such potential [unless he manifests them as wrathful skilful means]. Therefore, the enemy is the only one who gives us this golden opportunity. This is a remarkable conclusion, isn’t it! By thinking along these lines and using these reasons, you will eventually develop a kind of extraordinary respect towards your enemies.
~ The Dalai Lama (The World of Tibetan Buddhism)