Love responsibility. Say: "It is my duty, and mine alone, to save the earth. If it is not saved, then I alone am to blame.
Love each man according to his contribution in the struggle. Do not seek friends; seek comrades-in-arms.
Source, in full
The Saviors of God (1923), First Step : The Ego. Written in 1923; Published in English as The Saviors of God : Spiritual Exercises (1960) as translated by Kimon Friar; Excerpts later published in The Rock Garden : A Novel (1963)