Perfect Obedience Necessary

The importance of the Law as set forth in Matthew 5:17–20 is demonstrated in four ways. First, Jesus came to fulfill the law, not abolish it. Since the law reflects the moral character of the Person who gave it, Jesus, being Divine, could neither abolish nor replace it.

Second, the law protects God’s creatures “until all is accomplished” (v. 18). Christ came to save His people, not from obligation to the law but from its condemnation. When salvation is fully accomplished, the law will pass away as an external objective standard. The new covenant makes the law an internal guide for His people (Jeremiah 31:33, 34; Ezekiel 36:26, 27). The time will come when the character of the redeemed will correspond perfectly with God’s, making the law no longer necessary.   

Third, the law requires perfect loving obedience (vv. 19–20). The important aspect that is often missed is that loving obedience to God is the heart of Creator/creature relationship (Matthew 22:34–40). Law-keeping is not just observing rules in the hope of making one’s life better. Neither is God like the pagan deities, requiring certain routines and gifts to placate fickle whims.

On the other hand, many modern Christians live as though grace releases them from the law to live their own lives. They know that they ought to worship and serve the Lord if only they could talk themselves into it. They no longer keep the law since it is now regarded as an obsolete requirement from Old Testament days. True grace, however, teaches a different lesson because it puts within the believer a knowledge of Christ. The law of Christ (1 Corinthians 9:21; Galatians 6:2) gives Him the right to govern everything in a believer’s life. Grace calls on the saints to present their bodies as living sacrifices to God and to glorify Him in all that they do.

Fourth, Jesus informs us that, in His coming, the kingdom of God has invaded the kingdoms of the world (Matthew 3:2 cf. 4:8). The whole of the Sermon on the Mount is designed to inform Christ’s disciples of their duty to Christ in this new kingdom. The kingdom of God previously existed in Israel and was governed by the law of Moses. However, the trespasses and sins of Israel’s leaders were roundly condemned in this Sermon (v. 20; see Matthew 23:28). This failure brought about the change Christ was instituting (Matthew 21:43). The glorious truth is that when all is fulfilled, the renewed and holy character of the redeemed will enable them to live in perfect righteousness in the kingdom of heaven to the eternal praise and glory of God.

In the meantime, the teachings of this sermon inform Christ’s followers of their duties and privileges in the kingdom of heaven while they await the end and destruction of the kingdoms of the world and their full sanctification at the second coming of Christ. Thus, the saints are charged, “Seek first the kingdom of God and his righteousness” (6:33). Only in this way will their righteousness exceed that of the scribes and Pharisees.