We don’t believe that justification is a once in a lifetime moment. I’ll leave that one for my fellow Catholics on this thread to discuss since my plate is full right now.

However, we do believe that the moment we are justified, that that justification is
not incomplete. And by incomplete I mean that we are half-forgiven or half-saved (in it’s first stage) and have to make up for what is lacking. That is
not Catholic teaching.
Secondly, when we talk about works, we are talking about works done by the just because it is justification that makes those works sacrifices pleasing to God, that gives it a “sweet-smelling aroma (Phillipians 4:18).” Though I disagree with Matthew Henry on a number of points - for obvious reasons - he does make one point that I agree with in his commentary on James 2:
1. When Paul says that a man is justified by faith, without the deeds of the law (Rom. iii. 28), he plainly speaks of another sort of work than James does, but not of another sort of faith. Paul speaks of works wrought in obedience to the law of Moses, and before men’s embracing the faith of the gospel; and he had to deal with those who valued themselves so highly upon those works that they rejected the gospel (as Rom. x., at the beginning most expressly declares); but James speaks of works done in obedience to the gospel…
For Paul, “works of the law” are those works done in obdience to the law of Moses *prior *to coming to faith and being justified. Since these works are done while one is in a state of bondage to sin, they in no way can free us from that bondage because they fall short, which is Paul’s main point in Romans and Galatians. They are not rooted in faith and love and we cannot properly believe or love by our own natural powers, both are gifts of God. God must intervene. James is talking about works done by the just in obedience to the Law of Christ, the Law of Liberty. Unlike the works done prior to faith and justification, these works flow from a faith that works through love. Neither faith nor love can exist in a person who hasn’t been justified. Faith is the beginning and foundation of all things pertaining to salvation. Without it you cannot please God (Hebrews 11:6). Without faith, you cannot have love. Hence the presence of love is the objective evidence of faith. It is through love that faith is made manifest. The obective evidence of love is works, for love
must manifest itself in works. So when James says that faith is perfected by works, he means that faith is perfected by love, for he clearly attributes works to love:
James 1:25
25But one who looks intently at the perfect law, the law of liberty, and abides by it, not having become a forgetful hearer but an effectual doer, this man will be blessed in what he does.
Works naturally flows when one is fulfilling the law of liberty, namely, love. Like faith, the object of true love is
outward, not inward. Hence, love must
always be humble (1 Corinthians 13:4-5) - recognizing it’s
totaldependence on the One who is Love Himelf - and does not glory in itself. It gives glory to the One who is the proper object of love, God. And love of God automatically means love of neighbor, for one cannot exist without the other (1 John 4:20). The relationship between faith, love and the promised kingdom is made clear by James and reinforces what he said in later in chapter 2:
James 2:5
5Listen, my beloved brethren: did not God choose the poor of this world to be rich in faith and heirs of the kingdom which He promised to those who love Him?
God Bless,
Michael