Passage
Therefore, to one who knows to do the right thing and does not do it, to him it is sin.
Therefore, to one who knows to do the right thing and does not do it, to him it is sin.
James 4:15 Instead, you ought to say, “If the Lord wills, we will live and also do this or that.”
James 4:16 But as it is, you boast in your arrogance. All such boasting is evil.
James 4:17 Therefore, to one who knows to do the right thing and does not do it, to him it is sin.
The verse centers on "therefore", "knows", "right", and "does". It is saying that the verse draws attention to "therefore" and "knows", so its meaning should be read from those terms before moving to application.
The prior verse says "But as it is you boast in...", giving immediate footing for "therefore" and "knows". In James context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "therefore" and "knows" with trust shaped by these words, not by a vague optimism outside the passage.