Indeed, Luther was so certain of this, that he even added the word “alone” to the word “faith” in Romans 3:28 in his translation.
Therefore we conclude that a man is justified by faith alone apart from the deeds of the law.
I think when Paul referred to “the law” he meant the Law of Moses but this is sometimes confused with good work generically. Obviously we need a faith that works, but not according to the Mosaic law but the “Law of Christ.”