Just piggy backing on Jon’s explanation…hope it helps our understanding each other…
catholiceducation.org/articles/apologetics/ap0027.html
Justification by Faith
PETER KREEFT
The Protestant Reformation began when a Catholic monk rediscovered a Catholic doctrine in a Catholic book.
The monk, of course, was Luther; the doctrine was justification by faith; and the book was the Bible.
For everything is at stake here. The question is nothing less than how to get to heaven. Luther thought the Catholic Church was teaching not only heresy (heretics always call orthodoxy heresy, by the way) but another religion, another way of salvation, “another gospel” (Gal 1:6). That’s about as serious a charge as you can imagine. We need to examine this charge very carefully to justify the surprising claim that the fundamental dispute between Protestants and Catholics was due to a misunderstanding.
It certainly doesn’t look like a misunderstanding. It looks like a flat-out contradiction: the Catholic Church taught that we are saved by faith and good works, while Luther taught that we are saved by faith alone (sola fide). But appearances may be deceiving.
For one thing, even if the two sides did disagree about the relationship between faith and works, they both agreed (1) that faith is absolutely necessary for salvation and (2) that we are absolutely commanded by God to do good works. Both these two points are unmistakably clear in Scripture.
For another thing, the terms of the dispute are ambiguous or used in two different senses. When terms are ambiguous, the two sides may really disagree when they seem to agree because they agree only on the word, not the concept. Or the two sides may really agree when they seem to disagree because they agree on the concept but not the word. The latter holds true here.
When Luther taught that we are saved by faith alone, he meant by salvation only the initial step, justification, being put right with God. But when Trent said we are saved by good works as well as faith, they meant by salvation the whole process by which God brings us to our eternal destiny and that process includes repentance, faith, hope, and charity, the works of love.
This “faith”, though prompted by the will, is an act of the intellect. Though necessary for salvation, it is not sufficient. Even the devils have this faith, as Saint James writes: “Do you believe that there is only one God? Good! The demons also believe — and tremble with fear” (James 2: 19). That is why James says, “it is by his actions that a person is put right with God, and not by his faith alone” (James 2:24). Luther, however, called James’ epistle “an epistle of straw”. He did not understand James’ point (applied to Abraham’s faith): “Can’t you see? His faith and his action worked together; his faith was made perfect through his actions” (James 2:2 2).