Did you know that, in the Bible, the word “faith” and the word “belief” are both the same word. The real biblical word had a wide range of meanings, including “faith,” “belief,” “confidence,” and “trust.”
Interestingly, the King James translators chose to translate the verb form of this word as “believe” and the noun form as “faith.” This gives some the impression that there is a difference in meaning here, but those who wrote the New Testament would not have seen any difference.
Because of the range of possible meanings, the real meaning must be found in the context where this word is used.
In John 5:24 Jesus says that those who are saved will be saved because of their “belief” and then five verses later he says that those who are saved will be saved on the basis of what they have done. Obviously, Jesus used “belief” in a sense that would affect one’s actions.
In Hebrew 3:18-19, “unbelief” and “disobedience” are used interchangeably.
In Romans 3:31, Paul says that faith establishes the law, though he has already made it clear that observing laws has no capability to bring justification or salvation. His point is that the faith he was talking about would cause people to live as the law would have told them to live, though living this way could not earn any credit with God.
In James 2:14-26, James makes it clear that he is talking about faith that does not affect how a person lives, and he maintains that such a faith is dead and cannot bring salvation.
In Revelation 2:10 Jesus says, “Be faithful to death and I’ll give you the victor’s crown of life.”
In each of these cases it should be clear that saving faith necessarily involves being faithful, and there are many, many more passages that make the same point.
The best English equivalent is found in our common phrase, “You’ve got to have something to believe in.” When we use this phrase, the “something to believe in” is understood to mean something that shapes how you think and how you live—core principles that you would not intentionally violate.
This kind of faith in God would cause a person to try to live up to the moral requirements of God’s law thereby establishing the law (Romans 3:31). This kind of faith in God would make disobedience incompatible with belief (Hebrews 3:18-19). This kind of faith would cause a person to do what God wants (as Jesus indicated in John 5).
The bottom line—those with saving faith are faithful, those who are not faithful are not saved.