43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, Love your enemies and pray for those who persecute you, 45 so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 And if you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? 48 You therefore must be perfect, as your heavenly Father is perfect. 
One of the criticisms leveled against Christian author C.S. Lewis was that he did not particularly care for the Sermon on the Mount. Lewis responded that he supposed no one cares for the sermon. He said it was like being knocked flat on one’s face by a sledgehammer. He said he could not imagine a more deadly spiritual condition than that of a person who could read this sermon in peaceful pleasure.
Lewis gave an accurate description of how this sermon confronts any serious, believing reader or listener. The Beatitudes pound upon us with eight successively humiliating blows strong enough to make us question the genuineness of our faith. Then we are given the stunning metaphors of salt and light. Who among us can say we have fulfilled such a dynamic witness? Then comes the statement, “Unless your righteousness surpasses that of the Pharisees and the teachers of the law, you will certainly not enter the Kingdom of heaven” (v. 20).
Jesus follows that statement up by six strict illustrations of what our righteousness should look like as we exercise our Kingdom powers in this fallen world. Each example is incredibly demanding and utterly impossible to achieve in our own strength. Almost every line of this sermon, taken to heart, will flatten us. What God demands seems completely impossible. Christ’s teaching can be greatly discouraging. At the same time, the discouragement is evidence that the Holy Spirit is going about his re-creative work in us. The pain is evidence of spiritual life.
There is encouragement here as well. The fact that Jesus commands us to live this way means that it is possible to some degree to do so. It is possible for all of us to grow progressively in our faith so that the characteristics described in this sermon become increasingly evident in our lives. Jesus knows we can consistently (if not in perfectly in this world) reflect this extraordinary upside-down life.
That brings us to the crescendo of the sermon, the great commandment of love here in verses 43 through 48. One writer notes, “It is the most concentrated expression of the Christian love ethic in personal relations found anywhere in the New Testament.” How are we to treat others? Jesus began with his standard formula, “You have heard it said… but I tell you….”
LOVE LIMITED (43)
43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’” That was the traditional teaching as many rabbis understood it and as the people of Israel were taught to think. It was not, however, what the Old Testament actually said. Only the first part of the quotation is found in the Old Testament, “you shall love your neighbor,” is a word-for-word quote from the Greek version of the Old Testament from Leviticus 19:18.
The second part of the statement, “and hate your enemy” is not found in the Old Testament. It was an addition from the rabbis. They were convinced that the context of Leviticus 19:18 restricted the definition of neighbor to a fellow Israelite. They believed God’s direction of their historic relations with other peoples (like his command to exterminate the Canaanites and like the imprecatory psalms) actually called for this kind of hatred of others. They believed that God’s judicial pronouncements against other cultures granted them the right to hate individuals.
There was also the natural human tendency to approach a strong positive statement such as “love your neighbor” with a negative counterpart. God’s law does have positive and negative implications. They picked the wrong counterpart. God’s law was given to restrain hatred, not justify it. We know this because of the implication of other Old Testament passages that taught kindness towards one’s enemies, such as Exodus 23:4, 5:
4 “If you meet your enemy’s ox or his donkey going astray, you shall bring it back to him. 5 If you see the donkey of one who hates you lying down under its burden, you shall refrain from leaving him with it; you shall rescue it with him. 
Other parts of the law say the same. Deuteronomy 22:1-4 has a similar command, as does Proverbs 25:21. Paul quotes from this proverb when he instructs, “if you’re enemy is hungry, give him food to eat; And if he is thirsty, give him something to drink” (Rom. 12:20). By Jesus’ day, hatred of foreigners was so institutionalized that the Jews thought they were honoring God by despising any Gentile, collectively or individually.
The Qumran sect, in their writings, instructed their members to “love the brother; hate the outsider.” Outsiders clearly were not loved by God since God did not give his holy law to anyone but Israel. They believed there was no point in sharing God’s nature and his revelation with outsiders. Not very many Gentiles picked Palestine as a vacation destination.
LOVE UNLIMITED (44-47)
“44 But I say to you, Love your enemies and pray for those who persecute you.” Can we genuinely love those who have been hostile to us? Not as long as we live by the principles of the kingdom of this world, which at best encourages us to ignore our enemies, and at worst to retaliate against them. Only the Kingdom of God can provide the strong motive and power to help us love our enemies.
What Jesus commands is completely radical! “To return evil for good is devilish; to return good for good is human; to return good for evil is divine.” One commentator explains verse 44 this way:
The change from the singular “enemy” of v. 43 to the plural here may be intended to underline its comprehensiveness: there is no class of enemy which is excluded (cf. the very general “bad person” in v. 39). To “love” (agapaō) in the NT is not only a matter of emotion but also of an attitude which determines our behavior, acting for the good of the other … and is therefore appropriately expanded by the following clause, “pray for those who persecute you.” 
To the average unbeliever, the very idea of loving one’s enemies is absurd and offensive and completely beyond all human capabilities. It turns our natural sense of right and wrong completely upside down. To those under the Old Testament law, the idea of loving one’s enemies was completely contrary to their perception of the law, which they believed required rejection and hatred of enemies – a limited love.
Jesus commands love without limits, loving everyone regardless of what they say or do to us. That revolutionary act transcends any culture. The church will never change the world by ensuring that the right politicians are elected – assuming we could agree on who the right politicians are. The church will never change the world by its loud outcries against particular sins in the culture – no matter how vulgar those sins. But if the church were to practice love the way Jesus commands it might change our communities and our culture just as Rome was changed.
That being said, however, it is in our nature to treat the law as if it were a set of rules that enables us to earn a prize when we appear to be keeping it. We think that if we pray for our intolerable acquaintances God will change our enemies to suit our demands and improve our situations. He may choose to do that. But God may also answer your prayers by leaving you in conflict and persecution because he wants you to change!
Jesus gives two reasons for the kind of love that he commands. The first reason, found in verse 45, is that loving our enemies makes us like God: “that you may be sons of your Father in heaven, he causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.” The expression “sons of your Father” is a Hebrew idiom meaning to be like your heavenly Father.
If you impartially show love to your enemies as well as your friends, you will be like God, who displays his love by sending sun and rain to all people. Jesus is expanding upon what he said earlier in verses 21-22:
21 “You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ 22 But I say to you that everyone who is angry with his brother will be liable to judgment; whoever insults his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell of fire.
The second reason Jesus commands such love is that it distinguishes us from the world. He gives a negative example: “If you love those who love you, what reward will you get? Are not even the tax collectors doing that?” (v. 46). If we love only those who love us, there is nothing special about that. In fact, it’s perfectly natural because that is exactly how the world works. But it cannot show that we are different from the world.
The most hated and ostracized segment of Jewish society, the taxpayers, seen as traitors within the camp, still care for one another. Pagans follow that same principle. Even the disgusting, backstabbing tax collectors loved their friends. If a person loves only his friends, he or she is doing no better than a swindling tax collector.
It’s no big deal if you love your friends who love you back. Jesus underscores his point with his next statement in verse 47: “And if you greet only your brothers, what are you doing more than others? Do not even pagans do that?” Those who wish to follow Jesus should do more than what is common among the lost. That “more” is the distinctive quality of God’s love channeled from him through us.
The Christian is one who is above, and goes beyond, the unsaved person at their absolute best and highest. There are many people in the world who are not Christians and yet are very moral and highly ethical, people whose word is their bond, and who were scrupulous and honest, just and up right. But they are not Christian, and they don’t mind saying so. They do not trust into the perfectly-lived life and sacrificial blood-shedding death of the resurrected, ascended, and glorified Lord Jesus Christ.
Jesus is asking you to shine the light of his holy perfect law down into the dark recesses of your heart and measure whether there is “more” in your love. Is there something in the way you love that cannot be explained in natural terms? Is there anything unique about your love to others that is not present in the life of the unbeliever? If there is never an instance where there is a “more” to our love, if we love only those who are nice to us, we may not be Christians at all.
LOVE IN PRACTICE (44)
Jesus commands us to love our enemies. “But I tell you: love your enemies.” And our natural response is to ask how we could possibly do that. First, notice that Jesus is not commanding us to love our enemies in the same way that we love our loved ones, those near and dear to us. There are people for whom we have a natural, instinctive love. they require little effort to love because we just do.
Jesus is not asking us to have a romantic love, a friend love, or a family love, or an emotional love for our enemies. What he commands is a deliberate, intelligent, determined love, and indestructible goodwill toward them. What he is commanding us to do is the love of active sacrificial service for our enemies, loving them by the grace of Christ that is within you.
The rule is simple. Don’t spend your time navel gazing about whether you “love” your contentious neighbors. Just act to meet their needs. The New Testament’s primary word for “love” is one that conveys action, not feelings. There is hardly a verse in the New Testament that speaks of God’s love without also speaking in the same context of the cross. This suggests that to the biblical writers God’s love was to be seen there, not elsewhere.
Think of the verses. There is John 3:16: “For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.” Galatians 2:20: “I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me.” 1 John 4:10: “This is the love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins.” Romans 5:8: “But God demonstrates his own love for us in this: While we were still sinners, Christ died for us.”
In each case the cross is made the measure of God’s love. Moreover, it is not merely the fact of Christ’s suffering that makes God’s love so wonderful. It is also the fact that he suffered for sinners, and this means for those who were in themselves naturally repugnant to him. Picture in your mind the most contemptible person you know—the one who has wronged you or cheated you, a pervert, a murderer—imagine him drowning. Would you give your life for his?
It is not so easy to answer the question this time, for it now begins to show us something of the love of the Lord Jesus Christ for us. That is why the Bible says, “Very rarely will anyone die for a righteous man, though for a good man someone might possibly dare to die. But God demonstrates his own love for us in this: While we were still sinners, Christ died for us” (Rom. 5:7–8). It was while we were hideous to God that he loved us and died for us.
Many think that there is a good amount that they can achieve for themselves spiritually, but the Bible teaches differently. For one thing, it says that apart from God’s saving work through Christ natural man cannot understand Christ’s teachings. Jesus spoke even to the religious leaders of his day, saying, “Why is my language not clear to you?” and answered, “Because you are unable to hear what I say” (John 8:43). In other words, the natural man has ears to hear, but God’s Word is lost on him.
Second, the natural man cannot receive the Holy Spirit. For Jesus said to his disciples, “And I will ask the Father, and he will give you another Counselor to be with you forever—the Spirit of truth. The world cannot accept him” (John 14:16–17). This verse teaches that no one can be saved by receiving the Spirit as an act of his own will.
Third, the Bible teaches that the unsaved man cannot use his will to submit himself to God’s law. In fact, he is impelled to rebel against it. “The sinful mind is hostile to God. It does not submit to God’s law, nor can it do so” we are told in Romans 8:7.
Fourth, “The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned” (1 Cor. 2:14). The unsaved person cannot understand God’s truth. Finally, 2 Peter 2:14 says of the person apart from Christ that having eyes full of adultery “they never stop sinning.”
If we put all these teachings together, we see that God’s love is to be measured by the fact that while we were sinners and were unable to hear his word, receive the Holy Spirit, submit to his law, understand his teaching, or cease from sin Christ died for us. That is God’s love. That is the full measure of God’s love. It is that love to which we are called as God’s children.
The Lord sums this up with one hard sledgehammer blow: “48 You therefore must be perfect, as your heavenly Father is perfect.” God’s people should be different. It should be obvious that we are extraordinary because our Father is extraordinary. This is what Jesus means when he tells us to be perfect like the Father.
He is not assuming we can reach moral perfection in this life. Instead, he is reflecting on the way in which the love of the father is demonstrated in its perfection in the way he loves his enemies. When the Holy Spirit enables us to do that, we show that our love is not controlled by its object, but by God’s will, and by our Spirit-given commitment to the Father’s ways.
The mark of perfection in the Christian is simply that our love is not to be determined by the loveliness or the attractiveness we find in its object. It is not conditional upon being loved first. It is not directed only towards those who can return good to us.
If you have trusted into the person and work the Lord Jesus Christ, then your love is gradually being grown in the knowledge that when you were God’s enemy and a sinner, the Father first loved you. If you were to show the Father’s love, the family love, then you will reflect the father’s love for you to the unlovely around you.
All that Jesus has said in the description of the family of God in the Beatitudes confirms that we are not ordinary men and women. Different principles control our thinking and our living. We keep in step to the beat of a different, divine drummer.
There is only one basis upon which a person can love even his most offensive neighbors as he does himself (the essence of Christ’s teaching in this section). You know what it is. Jesus has told you in Luke 10:27 when he approved this statement:
You shall love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind, and your neighbor as yourself.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Mt 5:43–48.
 Hughes, R. Kent. The Sermon on the Mount: The Message of the Kingdom (Preaching the Word). Crossway. Kindle Edition.
 Ferguson, 102.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Ex 23:4–5.
 Ferguson. 103.
 Hughes, op. cit., quoting Alfred Plummer.
 France, 225.
 Boice, 142.
 Id., 142–143.