what does the bible say?
In modern English language, there is only a subtle difference between the words “faith” and “belief.” A common assumption is that “belief” conveys mental agreement about certain facts, while faith implies the same, but with a deeper emotional connection to some opinion or statement. For instance, a person may believe a boat can safely cross a lake, but they have not exhibited faith in that boat until they have boarded the boat and ridden it across the lake. So to some, belief means mental assent whereas faith means exhibited trust. The more pressing question, however, is what the Bible means when it uses the words belief and faith.
In both of the Bible’s primary languages—Hebrew and Greek—“belief” and “faith” include the idea of action that exhibits trust by living out one's faith or beliefs. Deuteronomy 26:17 says, "You have declared today that the Lord is your God, and that you will walk in his ways, and keep his statutes and his commandments and his rules, and will obey his voice." Placing their faith in Yahweh (the Lord) as their God meant that the people planned to loyally obey Him in all that He commanded. Faith and belief in the Bible always include the idea of loyal obedience.
James pointed out that naked factual agreement that Jesus is God's Son who died on the cross, was raised from the dead, and ascended into heaven, does not provide salvation. Even demons know those facts to be true and yet they are not saved (James 2:19). Salvation, rather, comes from aligning oneself under God's authority and swearing allegiance to Him. These are the concepts conveyed by the words faith and belief in the original languages of the Bible. Paul expressed the importance of the lordship of Christ in his letter to the Corinthians when he wrote, "For what we proclaim is not ourselves, but Jesus Christ as Lord, with ourselves as your servants for Jesus' sake" (2 Corinthians 4:5, emphasis added). Placing one's faith in Jesus means submitting to Him as lord or master with intention to obey His commands. Jesus said, "If you love me, you will keep my commandments" (John 14:15). Keeping Jesus' commandments is not a way to earn salvation, instead, it is a way to express one's love and loyalty to Him (cf. Ephesians 2:1–10). This attitude of love and loyalty (that results in obedience) is the belief and faith that brings salvation according to the Bible.