Faith is the only means by which we lay hold of the righteousness of Christ (Gal. 2:15–16). Jesus’ righteousness is the ground of our justification and is imputed to us when we trust in Him alone for salvation. The Father then declares us righteous in His sight, enabling us to inherit eternal life. This is accomplished entirely apart from any works we perform.
Roman Catholics, on the other hand, say that a combination of our faith and good works provides for our justification, fearing that the doctrine of justification by faith alone encourages people to live immoral lives. According to Rome, this doctrine might lead some to think that the casual acceptance of Jesus without any change in one’s life is the kind of faith that justifies.
This objection is easily answered through a careful outline of the biblical definition of faith, which the Protestant Reformers offered in response to the same Roman Catholic objections in the sixteenth century. Of course, John Calvin and the other reformers taught that true faith immediately manifests a changed life (James 2:14–26), and we will look at the scriptural teaching on this subject in due course. We are concerned today to look at the biblical definition of faith itself to show that faith is not merely a casual recognition that Jesus is the Savior.
Looking at Scripture, we can attribute to faith three essential aspects. The first of these is notitia — those things that we believe. We put our faith in something, or more appropriately, someone. In order to believe, we must know about that someone — the Lord Jesus Christ (Matt. 28:18–20; Acts 18:24–28).
Assensus, the second essential characteristic of biblical faith, is our conviction that the content of that faith is true. Many people know what orthodox Christianity teaches and yet consider it to be false (12:22–32). Genuine faith says that the content — the notitia taught by Holy Scripture — is true.
The final aspect of biblical faith is fiducia or personal trust and reliance. Notitia and assensus are not enough, as even demons know and believe the Christian creed (James 2:19). Faith is only effectual if, knowing the claims of Jesus and assenting to them, we personally trust in Him alone for salvation.