Our Lord said, in reference to the old Law,
“whoever therefore breaks one of the least of these commandments, and teaches men so, shall be called least in the kingdom of heaven” (Matt. 5.19).
An inquisitive reader asks: “but how can anyone, who breaks the Law of God, be regarded as part of the kingdom of heaven at all, even in the 'least' bit?” The question is deserving of a solid answer, requiring, first, the following background information.
The Pharisees were fond of categorizing the Lord's commands into those of "lesser" and "greater" significance. Those of "greater" importance were to be regarded as obligatory; whereas those of comparatively "lesser" value could, according to them, be disregarded with impunity (cf. Mk. 7.8-13; Matt. 15.6).
Our Lord came to put a stop to all such errors, and it is to this end that he makes his remarks in the passage in question.
Breaks
First, the term "breaks" (v.19) signifies the act of freeing from obligation, or "rendering them not binding" (Vine, 40). Hence, Jesus is addressing the habit of the scribes and Pharisees to bind some of God's commands, while "loosing" others, making those commands optional rather than essential.
Unequivocally, then, it was not our Savior who nullified the commands of God (for he came to "fulfill" them, v. 17), but the Pharisees. Thus, contrary to current thinking, when it came to keeping the Laws of God, Jesus was the "legalist," while the Pharisees were the ones who opposed the law (Mt. 23.28; cf. Mk. 7.9; Jn. 7.19; Acts 7.53; see "Lawless Legalists").
Least
Second, to demonstrate this distinction between Pharisaic doctrine and his own, Jesus implicates them using their own standard against them (cf. Matt.7.2). This is the gist of our Lord's remarks in verse nineteen.
When the Pharisees named a command of God, "least," they tossed it out (i.e., “broke” it), as though it didn't deserve to be counted among the realm of sacred obligations; equally so, Jesus, employing a play on the word, “least,” affirms: when the kingdom of heaven calls a Pharisee, "least,” it will 'break them,' for they are not worthy to be counted among the realm of sacred kingdom-inhabitants (v.20). Their attitude toward the smallest commands of God shall become Heaven's attitude toward them.
To name something, “least,” in this context, then, is as much as to say, “it is not worthy.” Hence, rather than admitting law-breakers into the kingdom (albeit with “lesser” honors), the Lord instead will disregard them altogether.
Indeed, the one who nullifies any of God's commands, however small or great, shall be called “not-worthy" in the kingdom of heaven.
The Syntax
Third, the expression, “least in the kingdom of heaven,” is syntactically misleading. The “name” ascribed to these law-shirkers would not be, “least in the kingdom of heaven,” but rather, simply, “least.”
The kingdom of heaven is the place in which that name will be bandied about — not the qualifier to the name itself. The original syntax separates the word, “least,” from the phrase, “in the kingdom of heaven.” Hence, our Lord says: “whoever therefore breaks one of the least of these commandments and teaches this to men, 'least,' shall he be called, in the kingdom of heaven.” Those who are in the kingdom of heaven are calling the law-breakers (who are not in the kingdom of heaven) “least.”
Furthermore, the preposition, “in” [to wit, "in the kingdom of heaven"], may be used as an “instrumental dative,” an equivalent of “by” — an action performed by an agent (cf. Matthew 4.1; Luke 4.1; 1 Cor. 12.13 — see also, Wallace, 372). Hence, even if we adopted the English syntax, the sense would be: “whoever therefore breaks one of the least of these commandments and teaches this to men shall be called, 'least,' by the kingdom of heaven.”
Thus, law-breakers are not here represented as in the kingdom of heaven, but are rather represented as unworthy/least, by those who actually are.
The Context
Fourth, the context of Matthew 5 is meant to demonstrate that, rather than relaxing the qualifications to inherit the kingdom of God, the Lord intended to enforce them.
In fact, the Law of God must be kept down to the smallest "jot" and "tittle" (5.18) -— the most basic letter and smallest diacritic in Hebrew and Greek. He concludes his remarks on the duties toward the Law in verse 20, saying,
"that unless your righteousness exceeds the righteousness of the scribes and Pharisees, you will by no means enter the kingdom of heaven."
Matching the Pharisees, whose standard of "righteousness" consisted of picking and choosing which commands to obey and which commands to set aside ("break"), would inhibit a Kingdom entrance.
Thus, it would be counter to the Lord's express affirmation to suggest that one may set aside a command of God, and yet still be numbered among the least of the kingdom inhabitants, for, he says, to the contrary, they "will by no means enter the kingdom of heaven.”
The Analogy of Scripture
Finally, there is a very vital principle of Biblical interpretation that is particularly apropos here. Always interpret seemingly nebulous and obscure passages in the light of other Scriptural principles which are plainer or less vague (see Terry, 449).
Scripture frequently affirms that a man may not set aside any of God's commands and expect to enter his heavenly kingdom (Jms. 2.10; Revelation 22.18-20; 2 John 9; Matt. 7.21-27). Man is never permitted to pick and choose which commands to obey and which to set aside, but is given "the whole counsel of God" in order to observe them without partiality (cf. Acts 20.27; 10.33; Gal. 1.6-9; 2 Pet. 3.1-2).
This principle is given, not because the Lord derives pleasure from man's external activities per se, but because he seeks the devotion of his subject. The true test of loyalty is experienced when a man is told to do something which, in his estimation, is either small, trivial, or repugnant (cf. Gen. 22.1-18; 2 Kings 5.1-14; Mt. 4.4).
Jesus said (Luke 16.10): "He who is faithful in what is least is faithful also in much (observing the smallest provisions of the Lord's will makes one a trustworthy and dependable servant in many things); but he who is unjust in what is least is unjust also in much" (setting aside a command of God on account of its relative "unimportance" is indicative of complete faithlessness).
Therefore, since the principle of keeping the Lord's commands, however small or great, is abundantly maintained throughout the Scriptures, our Lord could not be implying in Matthew 5.19 that one may deliberately disregard the "smaller" commandments and still enter the kingdom.
Classifications of God's Commands
Incidentally, we should not be misled into thinking that it is wrong to classify the Lord's commandments into those of greater and lesser significance.
Our Lord, both in person and through his apostles, indicated that some commands were indeed “greater” than others. He spoke of the "greatest commandment," to “love the Lord your God with all your heart, with all your soul, and with all your mind” (Mt. 22.37-38). The commandment regarding neighbor-love was, by him, esteemed as secondary (Mt. 22.39).
He likewise chastised the scribes and Pharisees for neglecting to keep the “weightier matters of the law” (Mt. 23.23). If there are weightier matters, there must be relatively lighter matters also.
What's more, Paul spoke of the three ever-abiding facets of the Christian life — viz., faith, hope, and charity. However, said he, “the greatest of these is charity” (1 Cor. 13.13).
The clash between our Lord and the scribes and Pharisees resided not necessarily in the practice of classifying divine law (though he certainly took issue with them relative to how they made those classifications), but in their disregarding them, owing to their perceived unimportance. Devotion demands the keeping of his whole counsel (Acts 20.27), not merely those with which you agree, whether small or great.
Perhaps no better statement of devotion is given than this, from the pen of David:
"I am your servant; give me understanding, that I may know your testimonies. It is time for you to act, O Lord, for they have regarded your law as void. Therefore I love your commandments more than gold, yes, than fine gold! Therefore all your precepts concerning all things I consider to be right; I hate every false way" (Psalm 119.125-128).
Conclusion
Matthew 5.17-20 is meant to demonstrate that the Lord was a keeper of the Law, in all respects; whereas the Pharisees and scribes maintained only portions of the Law. He warns his audience that if anyone should follow their example in this respect and teach other men to do the same, they will not be worthy to enter the kingdom of heaven.
Rather, men must do more than the scribes and Pharisees ("exceed" their righteousness), by keeping all of God's commands, if they wish to enter heaven. And just as the Pharisees neglected portions of God's Law by naming them, “least,” God will, in turn, neglect them by naming them, “least” — not worthy to enter that sacred refuge for the soul.
Terry, Milton. Biblical Hermeneutics. New York: Eaton & Mains, 1890.
Vine, W. E. Vine's Concise Dictionary of the Bible. Nashville, TN: Thomas Nelson, Inc., 2005.
Wallace, Daniel. Greek Grammar: Beyond the Basics. Grand Rapids, MI: Zondervan, 1996.