Jesus preached the greatest sermon ever, the Sermon on the Mount, found in Matthew chapters 5-7. Near the end of His sermon, Jesus spoke these words:
Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’
(Matt. 7:21-23)
Beginning in Matt. 7:13, Jesus has been applying His teaching earlier in the Sermon on the Mount. He begins with the exhortation to enter by the narrow gate (vv. 13-14) and continues with His warning to Beware of false prophets (vv. 15-20). Here our Lord cautions against those who make false professions of faith (vv. 21-23).
In the section immediately preceding this section, Jesus was warning of false prophets (vv. 15-20) who claimed to be speaking the truth but who were in fact telling lies. Jesus taught that a sure sign of a false teacher is not only that his doctrine is inconsistent with Scripture but that his actions are also inconsistent with the truth. In other words, false teachers speak lies masquerading as the truth and act out the lies in their lives. They are hypocrites.
In verses 21-23, Jesus first states His proposition (v. 21) “Not everyone who says to me ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven.” He then illustrates and elaborates on his proposition and demonstrates the implication of the proposition (vv. 22-23). These three verses must always be considered together. If verse 21 is separated from verses 22 and 23 then it allows people to claim that doing is more important to our Lord and this opens the door for a doctrine of salvation by works. And this is an incorrect understanding. By taking these three verses together as Jesus spoke them, it is impossible to emphasize works at the expense of belief.
Jesus is warning us of his concern for the danger of self-deception and self-delusion. He previously warned of how we could be misled by the false teachers and therefore not be saved. Here he is warning about the deception that comes from within ourselves that can result in our eternal damnation. As D. Martyn Lloyd-Jones wrote in his Studies in the Sermon on the Mount:
We are all in danger of being content with an intellectual assent to the truth. There have been people throughout the centuries who have fallen into this trap. They have read the Scriptures and accepted their teaching. They have been exponents of the truth and have argued against heretics. And yet their whole character and life have been a denial of the very truth they have claimed to believe.
D. Martyn Lloyd-Jones, Studies in the Sermon on the Mount (Eerdman, 1971, 1976), 519.
Readers of this portion of Scripture (vv. 21-23) must understand that Jesus is not talking about works righteousness here. He is teaching about belief. In the case of the false teachers, the hearers of the false doctrine are believing untruth. But in the case of the false professors, they may very well be speaking the truth but the problem in this case is that they do not believe. In both cases Jesus is talking about belief and in both cases the result of believing false teaching or not believing at all in spite of what the false professor says results in eternal damnation.
Jesus speaks of those in the church who have made a false profession of faith in that they claim the Lordship of Christ for themselves and they may even speak the word correctly but their hearts had never been given to Jesus and they had not practiced what they preached. The false teachers had been teaching lies but here, the false professors of faith may have been speaking the truth but in their hearts and in their actions they did not believe in the truth. They talked the talk but they didn’t walk the walk.
Therefore, the false teachers that Jesus described in vv. 15-20 “spoke lies that they claimed were the truth” while the false professors (of faith) “spoke the truth but lived a lie.” In a sense, both are false prophets. True Christians, those who believe the true word of God “talk the talk and walk the walk.”
Both the false teachers and the false professors practice deceit in their lives. The false teachers are deceitful in what they speak and the false professors are deceitful in who they are. But Jesus is stating unequivocally that though these false prophets may successfully work their deception in life, yet at the final judgment they cannot deceive the final judge, Jesus Christ.
It is interesting to note that these false teachers and false professors while standing before the Lord at the final judgment at the end of the age have the gall to continue to express their deception by saying to Jesus “Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?” (v. 22). They continued to give lip service to Jesus Christ himself even at the final judgment. This shows that both the false teachers and the false professors are equally unbelievers in this life.
Jesus replies that he has never known them even for a moment and then he announces the judgment “depart from me, you workers of lawlessness” (v. 23). We cannot fool Jesus. When we make our profession of faith, we need to search our hearts and make certain that we mean what we say. We must believe everything about Jesus — His life, His works, His love, His divinity, — everything. This is why the reading and study of the word of God and prayer are critical to the assurance of a Christian’s true belief. We should pray for conviction of our sins and for recognition of any false understandings of Christ that we may have. Our sincere belief assures that on the day of judgment we will not hear Jesus tell us “I never knew you; depart from me, you workers of lawlessness.”