C.s. Lewis said this quote

We have made men proud of most vices, but not of cowardice. Whenever we have almost succeeded in doing so, God permits a war or an earthquake or some other calamity, and at once courage becomes so obviously lovely and important even in human eyes that all our work is undone, and there is still at least one vice of which they feel genuine shame. The danger of inducing cowardice in our patients, therefore, is lest we produce real self-knowledge and self-loathing, with consequent repentance and humility.