That is, he who performs the will of God when he learns of it. Faith in God must accompany the doing, or the doing is only a form. It is true that “faith, if it hath not works, is dead, being alone” (James 2:17), but it is equally true that works unaccompanied by a sincere and living faith are also “dead” (Heb. 11:6). Those who do not know the will of God are not held accountable for it (Luke 12:47, 48), but those who have heard God’s voice speaking to their hearts and yet persist in ways of their own choosing “have no cloke for their sin” (John 15:22) and are in danger of presumption.

To address Christ as “Lord” is to profess the belief that He is indeed the Messiah, and implies that the speaker has assumed the role of disciple.

 The words “not” and “but” highlight the strong contrast between the mere talker and the actual doer of God’s will. Mere profession is worthless. He who pretends to know God and yet disobeys His commandments “is a liar, and the truth is not in him” (1 John 2:4), irrespective of any appearance to the contrary.