The well wisher had it within himself to answer his own prayer. His empty response revealed that he was not truly a Christian. Without active deeds of love and personal holiness, there is no mark of genuine faith in Jesus. Far from criticizing the necessity of faith, James distinguished between two kinds of faith. True saving faith will leave a trail of good deeds after it.
Salvation is by faith alone, but the faith that saves is never alone.
This aberrant view separated faith from works, saying that both can exist independently of the other. It is utterly impossible to see someone's faith without seeing his or her good works. Godly deeds are the external evidence of true faith within. James continued his discussion with the objector by commending his orthodox creed about the oneness of God. In verse 19, James turned from praise to pointed rebuke.