10 For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.” 11 Now it is evident that no one is justified before God by the law, for “The righteous shall live by faith.” 12 But the law is not of faith, rather “The one who does them shall live by them.” 13 Christ redeemed us from the curse of the law by becoming a curse for us—for it is written, “Cursed is everyone who is hanged on a tree”— 14 so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
It may be helpful to add, as a final comment on this passage, two sections from the Westminster Confession of Faith (chapter 16):
'We cannot by our best works, merit pardon of sin, or eternal life, at the hand of God, by reason of the great disproportion that is between them and the glory to come, and the infinite distance that is between us and God, Whom by them we can neither profit nor satisfy for the debt of our former sins; but when we have done all we can, we have done but our duty, and are unprofitable servants; and because, as they are good, they proceed from the Spirit; and as they are wrought by us, they are defiled and mixed with so much weakness and imperfection, that they cannot endure the severity of God's judgment.
'Works done by unregenerate men, although for the matter of them, they may be things which God commends, and of good use both to themselves and others; yet because they proceed not from a heart purified by faith; nor are done in a right manner, according to the word; not to a right end, the glory of God; they are therefore sinful, and cannot please God, or make a man meet to receive grace from God. And yet their neglect of them is more sinful, and displeasing unto God.'