Romans 3
27 Where is boasting then? It is excluded. By what law? Of works? No, but by the law of faith. 28 Therefore we conclude that a man is [i]justified by faith apart from the deeds of the law. 29 Or is He the God of the Jews only? Is He not also the God of the Gentiles? Yes, of the Gentiles also, 30 since there is one God who will justify the circumcised by faith and the uncircumcised through faith. 31 Do we then make void the law through faith? Certainly not! On the contrary, we establish the law.

Something interesting I read:
Doesn’t James contradict this in passages like James 2:14-26? How can we say that it is faith alone that saves, apart from the deeds of the law?
What James says, that man is not justified by faith alone, but also by works, does not at all militate against the preceding view [of justification by faith alone]. The reconciling of the two views depends chiefly on the drift of the argument pursued by James. For the question with him is not, how men attain righteousness before God, but how they prove it to others that they are justified;

Our works is how we prove to others that we are saved by grace. However, in God’s eyes, only faith will save us from an eternity apart from Him.