What shall we say then? Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it? (Romans 6:1-2 ESV)
Paul is explicitly addressing behavior there.
James addresses those that give intellectual assent to the reality of Jesus, but don’t let that knowledge provoke a response. Yet faith could hardly be more important to James, because faith the is the catalyst for action.
But someone will say, “You have faith and I have works.” Show me your faith apart from your works, and I will show you my faith by my works. (James 2:18 ESV)
The problem many of us children of the Reformation have is that we de facto assume that “justification” and “salvation” are interchangeable words. However, I am not alone in suggesting that “salvation” is a word that–depending on context, of course–can mean any and all of the following vocabulary:
I think we should broaden our idea of salvation out from simply the moment of justification. God has much more in store for us, including being saved from not only eternal damnation, but from all the sin in our lives. We see this past (Eph. 2:8)/present (1 Cor. 1:18)/future (Rom 8:23) idea of salvation throughout Paul. If we understand salvation in this holistic sense, then the idea of works (being performed solely via the merits of Christ as a result of our justification) playing a role in our total salvation isn’t at all at odds with Ephesians 2:8-9, etc.
N. T. Wright (2009) says in his Justification: God’s Plan and Paul’s Vision,
' Salvation' is from death itself, and all that leads to it and shares its destructive character... 'Salvation' does not mean 'dying and going to heaven,' as so many Western Christians have supposed for so long...this great rescue operation, this great renewal of all things, has already been launched in Jesus Christ, and is already being put into operation through the Spirit" (p. 235).
Bock, Darrell L. (1989). Introducing New Testament Word Analysis. In S. McKnight (Ed.), Introducing New Testament Interpretation. Grand Rapids, MI: Baker Academic. Buy on Amazon
Wright, N. T. (2009). Justification: God’s plan & Paul’s vision. Downers Grove, IL: IVP Academic. Buy on Amazon