It is the works of the Law of Moses that cannot save.
Galatians 2:16 Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
We are saved by faith.
But faith only exists where there are works of faith.
James explains very clearly.
James 2:14 What doth it profit, my brethren, though a man say he hath faith, and have not works? can faith save him? 15 If a brother or sister be naked, and destitute of daily food, 16 And one of you say unto them, Depart in peace, be ye warmed and filled; notwithstanding ye give them not those things which are needful to the body; what doth it profit? 17 Even so faith, if it hath not works, is dead, being alone. 18 Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works. 19 Thou believest that there is one God; thou doest well: the devils also believe, and tremble. 20 But wilt thou know, O vain man, that faith without works is dead? 21 Was not Abraham our father justified by works, when he had offered Isaac his son upon the altar? 22 Seest thou how faith wrought with his works, and by works was faith made perfect? 23 And the scripture was fulfilled which saith, Abraham believed God, and it was imputed unto him for righteousness: and he was called the Friend of God. 24 Ye see then how that by works a man is justified, and not by faith only. 25 Likewise also was not Rahab the harlot justified by works, when she had received the messengers, and had sent them out another way? 26 For as the body without the spirit is dead, so faith without works is dead also.
The works required of us are works of faith.
A work of faith is obedience to the commandments of Christ.
That is why he gave us commandments.
We must be ‘doers’ of the word and not just ‘hearers’.
James 1:22 But be ye doers of the word, and not hearers only, deceiving your own selves.
Luke 6:46 And why call ye me, Lord, Lord, and do not the things which I say? 47 Whosoever cometh to me, and heareth my sayings, and doeth them, I will shew you to whom he is like: 48 He is like a man which built an house, and digged deep, and laid the foundation on a rock: and when the flood arose, the stream beat vehemently upon that house, and could not shake it: for it was founded upon a rock. 49 But he that heareth, and doeth not, is like a man that without a foundation built an house upon the earth; against which the stream did beat vehemently, and immediately it fell; and the ruin of that house was great.
We are called to obey Christ. If we obey him, we build on a rock. If we don’t we build on sand.
In the parable of the sheep and goats they are judged on what they did or failed to do.
Matthew 25:40 And the King shall answer and say unto them, Verily I say unto you, Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me.
Matthew 25:45 Then shall he answer them, saying, Verily I say unto you, Inasmuch as ye did it not to one of the least of these, ye did it not to me.
We can’t earn salvation by what we do, but we can lose it by what we don’t do.
Luke 17:10 So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.
I hope you find this helpful.