Arguing over faith and works or faith alone is to miss the point. It’s usually the result of an incorrect understanding of justification and sanctification.
The Church teaches that justification only takes place through the merits of the passion, death and resurrection of Jesus. We do NOTHING on our own to bring about justification. Jesus earned it for us on the cross. Baptism is the means by which we are justified, and only has meaning because of Jesus.
Justification is a one-time event for each of us.
Once we are made right with God, then and only then can we be sanctified. Sanctification is the process of being made holy. That’s a work of God as well, but unlike justification, sanctification involves our cooperation with God. The Church teaches that we must willingly do what Jesus asks of us to be sanctified. Avoid sin. Practice corporal works of mercy. Pray. That kind of thing. These individual works merit nothing on their own, but merit everything through our cooperation with the will of Jesus.
Sanctification is an ongoing process.
Some Protestants teach that it ends with justification, but that’s incorrect. And in practice, no Protestant actually believes that a profession of faith is sufficient without actions which validate the truth of that profession of faith. We are not automatically sanctified once we are justified. Belief in automatic sanctification is belief in a faith without works, a dead faith (James 2:20). We must work out our salvation with fear and trembling (Philippians 2:12), hoping we persevere to the end (Matthew 10:22). We will only know we’re fully sanctified, fully made holy, when we’re in heaven (either directly or more commonly with a pit stop in Purgatory first for final purification). Not a moment before.