Answer
After exhorting his readers on the importance of humility (James 4:13–16), James warns, “To him who knows to do good and does not do it, to him it is sin” (James 4:17, NKJV). Other translations word it differently, but the thought is the same:
“Whoever knows the right thing to do and fails to do it, for him it is sin” (ESV).
“If anyone, then, knows the good they ought to do and doesn’t do it, it is sin for them” (NIV).
In this verse, James gives an example of a sin of omission. When believers know the right thing to do yet fail to do it, God holds them accountable for not doing it. So, it is not only what we do that matters to God; it is also what we fail to do. Inactivity could be as sinful as overt activity. Inaction might be judged the same as action.
Throughout his letter, James challenges his readers to action. They should be doers of the Word and not just hearers (James 1:22). If people are hearers but not doers, they are deceiving themselves. They should speak and act as people who are accountable (James 2:12). God has always made it clear what His expectations are (see Micah 6:8). We are duty bound to obey.
The Parable of the Good Samaritan contains two examples of people who knew to do good and did not do it. In Jesus’ story, a wounded and dying man lay on the road. A priest and a Levite both passed by the injured man without assisting him. In this, they sinned. They knew the right thing to do—the man needed help—yet they failed to take the action needed. In contrast, a Samaritan stopped and helped. He showed compassion to the injured man and demonstrated what it means to love one’s neighbor as oneself. He knew what was right, and he did it.
The implication of James 4:17 is that responsibility comes with knowledge. As we understand what is right, we are obligated to perform what is right. In Luke 12:47–48, Jesus communicates this principle: “That servant who knew his master’s will but did not get ready or act according to his will, will receive a severe beating. Everyone to whom much was given, of him much will be required, and from him to whom they entrusted much, they will demand the more” (ESV). When we understand what is good yet fail to act, we are held that much more accountable.
James links wisdom to “deeds done in the humility” (James 3:13). In several specifics, James calls people to take action—to do what they know is right. Do they wish to be close to God? Then they should draw near to Him (James 4:8). Do they wish to be exalted? Then they should humble themselves (James 4:10). For each desired result, there is a necessary preceding action, and we are held accountable for doing what we ought to do. “It is sin to know what you ought to do and then not do it” (James 4:17, NLT).
James’ entire letter is committed to the necessity of living, active faith. In James 2:14–17, he writes, “What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? If a brother or sister is poorly clothed and lacking in daily food, and one of you says to them, ‘Go in peace, be warmed and filled,’ without giving them the things needed for the body, what good is that? So also, faith by itself if it does not have works, is dead” (ESV). Good works will always accompany genuine faith (see Matthew 5:16). Knowing the right thing to do is important; the follow-through is just as important.