한국어 日本語(Please do not misunderstand the intention of this article. I am not saying that believers do not do good works. It is unquestionable that believers do good works. 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. 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 justification and sanctification. What it means in the realm of justification is what it must mean in the realm of sanctification. If it bears no fruit and has no transformative power in the realm of justification, then it bears no fruit and has no transformative power in the realm of 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 form of the verb believe. Faith could more literally be translated as belief. It is described as 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 justifies, being the plain belief or persuasion of mind that accepts the testimony about what Christ accomplished on the cross as being true. If we believe that Christ did it all, then we must be "idle" and just receive the glad tidings of His finished work. However, this idle faith is extremely offensive to people, especially theologians and religious 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 includes works or 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 (i.e., the type of faith that caused him to be slandered as an antinomian in Romans 3:8). Regrettably, the faith taught by James and Paul is repudiated 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 when works and faith are combined like this, including the synergistic effect, create a positive correlation between faith and works. This is vastly different than saying that faith produces works and is evidenced by works. If such were true, then works would be inherent to faith and salvation would be by works. (See my articles here, here, and here for more information.)
Too much is at stake to be indifferent about this. If we misunderstand the nature of faith, then we get the doctrine of justification by faith wrong and are left looking at our works. So, let's not make the mistake of falling into a scheme of works salvation by thinking that faith produces works or is evidenced by works. See my article What Is the Gospel and the Nature of Faith? for more information.