But I think this is a misreading of Paul. The full text from Romans is 3.28 is this (emphasis added):
For we maintain that a man is justified by faith apart from works of the Law.What are these "works of the Law"? If you read Paul and pay attention to the narrative in Acts you come to see that "works of the Law" mainly had to do with submitting to circumcision. This is most clearly seen in Acts 15 and Galatians. Basically, what Paul is saying is that Gentiles who want to be justified before God don't have to become Jews. Protestants have tended to miss this, missed that Paul's discussions about faith are about the Jew/Gentile issue rather than about daily moral performance.
Because when we do get to daily moral performance Paul seems to suggest, in a variety of places, that it creates merit. In these locations Paul sounds a lot like Jesus and James. Consider the ending of Galatians, a founding document (along with Romans) of the Reformation's doctrine of sola fide:
Galatians 6.7-10"A man reaps what he sows."
Do not be deceived: God cannot be mocked. A man reaps what he sows. Whoever sows to please their flesh, from the flesh will reap destruction; whoever sows to please the Spirit, from the Spirit will reap eternal life. Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up. Therefore, as we have opportunity, let us do good to all people, especially to those who belong to the family of believers.
"Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up."
That sounds like merit to me. And it's a teaching found not with Jesus or James...but in Galatians.