Belief used to mean “trust in God,” while faith meant “loyalty to a person based on promise or duty” (a sense preserved in keep one’s faith, in good (or bad) faith and in common usage of faithful, faithless, which contain no notion of divinity). But faith, as cognate of Latin fides, took on the religious sense beginning in 14c. translations, and belief had by 16c. become limited to “mental acceptance of something as true,” from the religious use in the sense of “things held to be true as a matter of religious doctrine” (a sense attested from early 13c.).