We never get hurt by too much compassion, but we’re hurt all the time by unwise trust. Compassion makes you less likely to trust unwisely. With compassion you see the depth of other people’s vulnerability and can more intelligently assess his or her defenses against it, which are usually resentment, anger, or some kind of abuse. Compassion must be unconditional in love relationships, but trust has to be earned, especially once it’s betrayed. Compassion gives a couple room to earn trust by disabling the automatic defense system that takes over resentful relationships.
— Steven Stosny, Soar Above, p. 192