James 2:24 tells us that a person is saved “by works and not by faith alone.” Some translations will use the word “justified” instead of “saved,” but St. James is using that word broadly in a sense we don’t use it today, so it is safe to read it as “saved.” I think many of us are generally familiar with the debate that Protestants and Catholics have over faith and works. If you have ever done the research and tried to get to the bottom of it, you probably found a lot of confusing information and terminology. Allow me to simplify the Catholic understanding of this question. I will not explain what Protestants believe because they believe different things, depending on which denomination or individual you are interacting with. You are best served studying what the Church teaches and then contrasting that with any other ideas you come across.
Catholics believe that our salvation is a movement from a “state of sin” to “justification” to “sanctification.” I will explain what these things mean and show how they eventually relate to works.
The state of sin is the state in which we are all born. Our souls are tainted by Original Sin, and we have no friendship with God.
Justification is when we are healed of this sin and restored to friendship with God. Once we have been “justified,” we are in a state of grace. This means we will go to heaven if we die. How are we justified? Through faith and baptism! If you have faith in Christ and are baptized, God accepts you as his son or daughter, and he infuses into your soul the grace necessary for heaven when you die. Catholics do believe that this state of justification can be lost. If you commit a serious enough sin, you will return to the state of sin. For this very situation, Christ instituted another sacrament which is called “reconciliation.” Receiving this sacrament is essentially like being re-baptized. When a person goes to confession, he is healed of his post-baptism sins and restored to friendship with God. He is re-justified. So far so good…
Sanctification is what happens after we are justified. The Church teaches that obviously a baptized person still has a lot of room to grow in holiness. God doesn’t settle for the bare minimum. He always leads us in grace to constantly improve until we are the perfect saints he made us to be. This process of getting holier and holier after justification is called sanctification. How does it happen? How do we get holier? Among other things, through good works! You get holier and God gives you grace when you do good things for other people. You have to feed the hungry, clothe the naked, and give yourself to other human beings in order to be fully saved. This is why Catholics say we need “faith and works” to be saved—because being saved means being a saint, not just getting to heaven.
There is one more piece that we need to add to the puzzle. James 2:17 warns: “faith of itself, if it does not have works, is dead.” What does this mean? What St. James is trying to convey is that sanctification requires good works, and sanctification automatically follows justification. Unless you die the moment after going to confession or being baptized, you have a whole lifetime to fill with actions that you choose. The warning James puts forward is that if you aren’t doing good works and moving through this process of sanctification, you might not be justified. Why would this be the case? Because God isn’t satisfied with mere justification. Once you have been justified, you can count on him leading you to be sanctified. So if you aren’t doing good works, maybe your faith is actually dead and you need to go back to confession (or baptism if you haven’t been baptized yet!). Put very simply, after step 1 (justification), God will start on step 2 (sanctification), so if it doesn’t look like you’re on step 2, you may not have completed step 1.
So what does faith do? It allows us to be justified. What do works do? They allow us to be sanctified, and they indicate that we’ve already been justified.