πίστις
pístis
pis'-tis
from πείθω; persuasion, i.e. credence; moral conviction (of religious truth, or the truthfulness of God or a religious teacher), especially reliance upon Christ for salvation; abstractly, constancy in such profession; by extension, the system of religious (Gospel) truth itself.

KJV translates as: assurance, belief, believe, faith, fidelity