It's said that the Buddha first taught lovingkindness or metta meditation as an antidote to fear. According to legend, he sent a group of monks off to meditate in a forest that was inhabited by tree spirits. The tree spirits resented the monks' presence, so they decided to scare them away. They transformed themselves into ghoulish visions, made terrible shrieking sounds, and created awful smells. The monks, appropriately terrified, fled the forest. “Please Lord Buddha,” they begged, “send us to meditate in some other forest.”
The Buddha said, “I'm going to send you back to the very same forest—but this time, I'll give you the only protection you need.” And so the Buddha gave the first-ever teaching of metta meditation. He encouraged the monks to recite the phrases of metta—but more important, to actually do the heartfelt practice of lovingkindness.
Like many such stories, this one has a happy ending. It's said that the monks returned to the forest and practiced metta. The tree spirits were so moved by the energy of lovingkindness they generated that they decided they quite liked the monks being there after all. They decided to serve and protect them.
Whether this parable is literally true, its inner meaning endures: A mind filled with fear can be penetrated by the quality of lovingkindness. Moreover, a mind filled with lovingkindness cannot be overcome by fear.