The Roman Catholic Church adds works to salvation. It denies that we are justified by faith alone in Christ alone. It adds sacraments (CCC 1129), baptism (CCC 1257), penance (CCC 980), and the works of the Law (commandments) as necessary for salvation (CCC 2068, 2036, 2070). The Bible teaches that keeping the commandments is not necessary for salvation (
Romans 3:28,
4:5,
Gal. 2:16,
21) and is to be avoided (
Gal. 5:1-5). Otherwise, what Paul says in
Romans 4:5 wouldn’t be true, “But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness.”
The Roman Catholic Church preaches a false gospel.
We have to be careful and understanding about this issue, because many try to pit Paul and James against each other when in reality they're saying the same thing and even referencing the same OT sources. Keep in mind that James was written first, when the Church was almost exclusively Jewish and was thus writing to an audience that was accustomed to living under the Law. Jesus left behind commandments that we are to obey, and very likely some of the New Jewish believers were very happy to throw off the Law and live freely for themselves. James is trying to remind them that they are expected to show their faith to a hostile world through the way they lived and that Jesus has expectations for their lives.
Paul, OTOH, was writing to an audience composed of Jews and Gentiles both and emphasized that faith justifies us before God, that we simply cannot earn it, no matter how good we think we are. There were doubtless Jewish believers within the early church that considered themselves superior to Gentile believers because they obeyed the Law while the new believers did not. In fact, Paul and Peter famously argued over whether to insist the new believers essentially convert to Judaism and be put under the Law. Paul is simply reminding us that, in Christ, no one is to consider themselves more righteous than any other because of their obedience to a set of rules. Something else we need to understand is what faith is. It's not, "Oh, yes, I believe in Jesus". No, it's more a daredevil crossing Niagara Falls on a rope with a wheelbarrow who then asks the crowd if they believe he could put one of them in the wheelbarrow and go across the falls without dropping them. Faith means you get in the wheelbarrow. It's putting complete and total trust in Jesus, which of course means we're going to do what He says to do.
Our mistake is to ignore either side of the coin. Both faith and works go together, and here's how. Faith justifies us before God, full stop. We see this in the thief hanging on the cross beside Jesus. He had no good deeds to offer, no sacraments, no catechisms, no baptism, only faith, and Jesus accepted him. We sometimes forget, however, that Jesus gave us commands and even stated explicitly that His followers would OBEY His commands. And what were those commands? The two most important ones are to love God with everything we have and to love our neighbors as we love ourselves. The entire Law is wrapped up in those two, and what do they mean practically? If you love God, you will seek to do what He does, which is love. And if you love your neighbor, how are you going to ACT towards him? Doesn't this start to sound like some of the things Catholics are saying?
Let's be honest here, can someone really say they are a follower of Christ if they then proceed to knowingly and habitually ignore the commands Jesus gave us? Do I love my wife if I say I do, then ignore her or treat her like dirt?
There are two extremes that we need to avoid. One is to say that I can be saved then live selfishly for myself, ignore everything Christ taught and still be welcomed into God's eternal presence. Wrong because you came to Him under false pretenses, not fully committing yourself to Him. The other extreme is to live in constant fear that I'm not doing enough, that I have to contribute to my own salvation, that my desire to obey Christ isn't enough, that I have a set number of church specified activities that I must carry out in order to be welcomed into God's eternal presence. Also wrong. God doesn't want us to live under condemnation and fear, and He doesn't want us counting up our deeds, hoping that there are enough good ones to outweigh the bad ones.
So, what is the Christian to do? First, trust completely that Jesus has you. Satan, the world, and sadly, even some in the church will try to tell you that that you're not doing something right, that you don't belong to the right group, you're not doing enough or you're not doing the right rituals. Bunk. If you put your faith in Him and you try every day to learn more about what He wants from you, how He wants you to act, etc., He has you. Second, keep studying, keep paying attention to the Word, keep loving your neighbor as God directs. Jesus has done everything necessary for you to be welcomed into God's eternal presence.