Subliminally, the Buddha was saying, we are all tending these fires (of greed, hatred, and delusion), motivated as we are by our insecure place in the world, by the feeling, the dukkha, of not fitting in. The fires of greed, hatred, and delusion are defenses against acknowledging that everything is on fire, instinctive attempts at protecting ourselves from what feels like an impossible situation. The Buddha stressed the burning nature of the world in order to show his listeners what they were afraid of.