In Catholicism, works do not justify us; only God can do that. But once justified, by faith, now with Gods seed in us, one must work out their salvation together with He who works in us (Phil 2), by the Spirit, with the grace received, making it a cooperative effort. Consider the Parable of the Talents. The more given, in terms of grace, time, opportunity, knowledge, gifts of the Spirit, etc, the more that would be expected, with God knowing the heart as only He does and judging accordingly.
It’s all grace, both faith and these works. Examples of the criteria for judgment include obeying the commandments (Matt 19:17), those things done for “the least of these” (Matt 25), doing good, (Rom 2:7), putting to death the deeds of the flesh (Rom 8:12-13), works prepared for us in advance (Eph 2:10), being holy, (Heb 12:14). These are all now based on love, the nature of God whose image we’re to be transformed into, the love that the Spirit pours into our hearts (Rom 5:5), and so the church, quoting a 16th century believer, sums it up with,
“At the evening of life we shall be judged on our love.”
This is what faith, by establishing fellowship with God, should lead to. So the most important New Covenant prophecy:
“I will put my law in their minds
and write it on their hearts.
I will be their God,
and they will be my people.
No longer will they teach their neighbor,
or say to one another, ‘Know the Lord,’
because they will all know me,
from the least of them to the greatest,”
declares the Lord.”
“For I will forgive their wickedness
and will remember their sins no more.” Jer 31:33-34
Then:
“To those who by persistence in doing good seek glory, honor and immortality, he will give eternal life.” Rom 2:7
“For it is not those who hear the law who are righteous in God’s sight, but it is those who obey the law who will be declared righteous.” Rom 2:13
“But now apart from the law the righteousness of God has been made known, to which the Law and the Prophets testify.” Rom 3:21
“But now that you have been set free from sin and have become slaves of God, the benefit you reap leads to holiness, and the result is eternal life.” Rom 6:21
“And so he condemned sin in the flesh, in order that the righteous requirement of the law might be fully met in us, who do not live according to the flesh but according to the Spirit.” Rom 8:4
“Therefore, brothers and sisters, we have an obligation—but it is not to the flesh, to live according to it. For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live.” Rom 8:12-13
“Love does no harm to a neighbor. Therefore love is the fulfillment of the law.” Rom 13:10
And that love, a work of God’s in us, is both a gift, and, in order to be love, also necessarily a human choice.