
(In this article, I am not saying that believers do not do good works. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them. However, it is a dangerous error to say that faith produces works. This is a distortion of the Gospel and results in works salvation.)
A correct understanding of the Gospel should by implication result in a correct view of faith. If Christ really did it all, then there is nothing left for the sinner to do but to recognize the grace of God in Christ. In this manner, God is truly able to justify ungodly people who don't work (Rom. 4:5). To say that faith produces works is to suggest that works are inherent in faith. In other words, faith would include a works-producing principle, making it essentially a law of works in itself. This, in turn, requires something more of the sinner than the finished work of Christ and nullifies the grace of God.
Faith isn't something that changes in meaning between the initial experience of justification by faith and the subsequent life of progressive sanctification. What it means in the realm of justification by faith is what it must mean in the realm of progressive sanctification. If it bears no fruit and has no transformative power in the realm of justification by faith (being forensic in nature rather than ethical), then it bears no fruit and has no transformative power in the realm of progressive sanctification.
When describing faith, it is necessary to show two things: what it is and what it isn't. What faith is is described in Hebrews 11:1 and 1 John 5:9-13. What faith isn't is described in Romans 3-4, Galatians 3, and James 2.
Let's start with what faith is. Faith is the noun cognate of the verb believe. Faith could more literally be translated as belief. It is described as the assurance of things hoped for and the conviction of things not seen in Hebrews 11:1. The Apostle John in 1 John 5:9-13 describes it as receiving testimony as being true.
Next, let's look at what faith isn't. Paul, in Romans 3-4, says that faith is apart from works. Faith and works are antithetical in the same manner that grace and works are antithetical (Rom. 11:6 KJV). Moreover, Paul clearly tells us that [the works of] the law are not from faith (Gal. 3:12). If works are not from faith, then works are not inherent in faith and faith cannot be likened to a fruit tree that brings forth its fruits as evidence of salvation. In like manner, James says that faith apart from works is idle (literally "dead"), and thereby incapable of doing anything by itself. It is like a body without a spirit. (See my commentary on James 2:14-26 here for more information.)
It is this "idle faith" that is present in justification by faith, merely being persuaded that what Christ accomplished on the cross is true. If we believe that Christ did it all, then we must passively (idly) receive the testimony about His finished work. However, this idle faith is extremely offensive to people. As a result, people refuse to take James' words at face value. Instead, they assume that James was equivocating as to the meaning of the word faith, sometimes meaning inauthentic faith and sometimes meaning authentic faith, and then wrongly interpreting James as if he taught that authentic faith produces works. However, James was not equivocating. He spoke of the only type of faith that exists, which by itself is idle and incapable of doing anything. He spoke of the same type of faith that Paul spoke of. Regrettably, the faith taught by James and Paul is disdained by the Christian churches (including the Free Grace and Reformed churches as described here, here, and here).
According to James 2 and Galatians 5:6, works can be added to this "idle faith." The good things that happen by combining faith and works create a positive correlation between faith and works. The relationship between faith and works is correlative, not causative. (See my articles here, here, here, and here for more information.)
Too much is at stake to be indifferent about this. People who say that faith produces works have misunderstood the Gospel and are trapped in a system of works salvation.