“So whoever knows the right thing to do and fails to do it, for him it is sin.” ~ James 4:17
Explanation of the Text: This final statement here seems to be arbitrary and thus, is difficult to understand in connection to the text. For that reason, some have suggested that it should actually be its own paragraph, or perhaps that it should go at the end of the epistle. However, God has purpose in every word that has been placed in Scripture, and the verse must be looked at in the context of the other parts. James has just admonished the people for making plans that don’t consider God, but he has just told them this is a wrong way of living. “As Jewish Christians, those rebuked well knew that they should be actively engaged in such activities in conscious dependence upon God’s will. In pausing to reflect, they were well aware that their self-centered boasting was displeasing to God.”
Based on this understanding, it is logical that James can reach the conclusion that failing to do what is right, especially if one knows the right thing to do, is therefore in sin. James has just told them the right thing to do is the will of God, and therefore, if they fail to do it, they are in sin. The fact that James has just told them what to do, they are now without excuse and if they continue in the same sin, they are doing so not out of ignorance, but out of willful ambition. “They cannot take refuge in the plea that they have done nothing positively wrong; as Scripture makes abundantly clear, sins of omission are as real and serious as sins of commission.”
Examination & Application of the Text: Simply put, every person is called to do the right thing. In this context, the right thing to do is the will of God, and live life as one who is dependent on Him. The only way to know the right thing to do, that which is God’s commanded will is found in Scripture. Therefore. One must be in the Word of God continuously, not simply to study and learn it, but to apply it to daily living. God has commanded, therefore, we are to walk in obedience of it.
 D. Edmond Hiebert, James, (Winona Lake: BMH Books, 2009), 256.
 Douglas J. Moo, James: An Introduction and Commentary, vol. 16, Tyndale New Testament Commentaries (Downers Grove, IL: InterVarsity Press, 1985), 163.