In the Dune novel, the Bene Gesserit used the following chanted words to reduce their fear.

"I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will allow my fear to pass over me and through me. And when it has gone I will turn my inner eye to see its path. And where the fear has gone there will be nothing. Only I will remain."

(extracted from, GPL'ed text)