The purpose of the training - Anguttara Nikaya 11.1

Ananda asked Gotama, what is the purpose of developing skill and strength? What is the purpose of the practice?

The Buddha said, freedom from remorse becomes possible to attain with skill and strength. Joy is possible with freedom from remorse. Peace and love is possible with joy. Serenity is possible with peace and love. Pleasure is possible with serenity. Concentration is possible with pleasure. Understanding - of the Dharma, of things as they actually are, of duty - is possible with pleasure. Disenchantment - freedom from maya - is possible with understanding. Dispassion and rational behavior is possible with disenchantment. Renunciation and release - Sannyasa - is possible with dispassion and rational behavior. This in turn permits freedom from distress, nirvana - the consummation of this arahantship is the achievement of the purpose of Brahmacharya.