The key discipline you must cultivate is Ahimsa (Absence of Violence). It does not merely mean not injuring a living being. You should not cause hurt even by a word, a look or a gesture. Tolerance, fortitude, equanimity - these help you to be steady in Ahimsa. They will remove all chance of your causing pain to others. This is called Sahana (Forbearance) or Kshama (Forgiveness). Assess the worth of whatever others do to you or say about you, and cultivate fortitude and the understanding to appreciate their behavior and pardon their faults. This capacity is as invaluable as truth, righteousness, renunciation and compassion. This is all that one need to possess for spiritual advancement.

-Divine Discourse,  February 17, 1980.

A Pure Heart is all Sadhana - Baba