Our serenity, our acceptance of our karma in all occurrences, strengthens our will. We grow stronger in facing life with serenity, never weaker. Through anger and impatience we become weak. In the face of every occurrence we are strong when we are serene. On the contrary, we become continually weaker in will through moroseness and an unnatural rebellion against destiny.
Source: Rudolf Steiner – GA 130 – Esoteric Christianity and the Mission of Christian Rosenkreutz – Lecture 2 – Leipzig, 5th November 1911