Strong's G4102 — πίστις (noun)
pistis (pis'-tis) n.
1. persuasion, i.e. credence
2. (morally) conviction (of religious truth, or the truthfulness of God or a religious teacher)
3. (especially) reliance upon Christ for salvation
4. (abstractly) constancy in such profession
5. (by extension) the system of religious (Gospel) truth itself
[from G3982]
KJV: assurance, belief, believe, faith, fidelity 
Root(s): G3982 
Hebrew root: πείθω
Occurrences: 243