English Theasurus that shows all the ways the English word is translated from the original Greek and Hebrew.
English Theasurus from the Hebrew and Greek Strong's Dictionary
belief 4102 ** pistis ** assurance, {belief}, believe, faith, fidelity.
unbelief 0543 ** apeitheia ** disobedience, {unbelief}.
unbelief 0570 ** apaistia ** {unbelief}.