Cowardice is the belief or faith in the possibility of survival – of the body, or of some aspect of existence to which we adhere. It is also a lack of appreciation for oneself which comes from a lack of appreciation for others – and a lack of appreciation for the wider context of being human. When the need to survive takes precedence over appreciation – cowardice is born.
You could try another approach—but be warned it is far more threatening: Always put the possibility of joy before the need to be safe.
p134-135, Emailing the Lamas from Afar, Ngakpa Chögyam and Khandro Déchen, Aro Books, 2009, ISBN 978-0-9653948-5-7