What are the purposes of the Buddha's preaching?

 In the First Sermon, Dhammacakkappavattana Sutta (the Discourse of the Turning of the Wheel of Dhamma or Truth), the Buddha pointed out the Middle Way which gives vision, which gives knowledge, which is conducive to calmness, insight, enlightenment and Nibbana (the state of being free from all defilements and suffering).

In one of His discourses, the Buddha summarized His teaching with the words "Vimutti or Spiritual Freedom from all defilements and sufferings in the Ultimate."

When sending His first sixty disciples on their preaching tour, the Buddha said:

"I, now, monks, am free from all bonds of gods and men. And you too, monks, are free from all bonds of gods and men. Travel, monks, for the welfare of the many, for the happiness of the many, for helping the world, for the good, welfare, and happiness of gods and men."

From Buddha's words, above mentioned, we can say that Nibbana or Vimutti is the main purpose of the preachings of the Buddha. He encouraged His disciples to walk the Middle Way in order to eradicate all defilements and sufferings and then, out of compassion for all, lend a help hand to others.

In brief, Buddha taught people how to be happy and prosperous in a worldly as well as a spiritual sense. Those who follow His teachings can select their way of life practicable for themselves.