27 “You have heard that it was said, ‘You shall not commit adultery.’ 28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. 29 If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. 30 And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell. 
If you haven’t picked up on it yet, the section of Jesus’ Sermon on the Mount we are studying (5:17-48) focuses on the fulfilment of the Old Testament law in Christ’s Kingdom. It is the most extensive discussion of this issue anywhere in the gospels. It raises acutely the issue of Jesus’ messianic authority and the existing authority of the Torah and its authorized interpreters.
But its tone is not primarily argumentative or negative. It sets out with a series of graphic examples the sort of obedience to the will of God to which the Old Testament law could only begin to point the way. This radical approach to discipleship goes far beyond the best righteousness that the scribes and Pharisees could imagine (5:20); its goal is nothing less than sharing the perfection of God himself (5:48).
The first topic of this section are Jesus’ general principles of the law (5:17-20). Then, last week, we looked at the first of six examples showing what true law-keeping is supposed to look like in God’s Kingdom. The scribes and Pharisees taught that if one did not shed human blood, one could not be guilty of murder. Christ then added the radical new take that the prohibition against murder was because of the value God places upon a selfless view of human relationships.
Jesus started with the example of murder because everyone could agree that there is no circumstance in which cold-blooded murder is acceptable. However, Jesus upped the ante by declaring that thinking ill of another person, demeaning them to a level of nothingness because of the way they have interfered with your wants and desires, is also murder. And, as we learned last week, there was no acceptable sacrifice a murderer could make under the Mosaic law to remit his sin. A convicted murderer stood under a physical and spiritual death sentence.
To drive that point home, Jesus used the example of someone who becomes aware that a fellow Israelite has a grudge against him. Jesus said that person must leave their sacrifice at the temple and immediately travel back home to make things right with the offended person. His point was that no amount of religious ceremony could cover over a selfish, sinful, heart full of murderous intent. Jesus has just taken a law that seems manageable and doable and turned it into something completely deadly for every human being who has ever held ANYONE in contempt.
In this 4-verse example before us this morning, Jesus uses another death penalty offense under the Mosaic law: adultery (Ex. 24:4; Lev. 20:10-21). The Old Testament penalty for adultery was death. But for all practical purposes, the scribes reduced this law to, “you shall not be found guilty of committing adultery.”
In some cases, they lessened the severity of this law and its punishment by making divorce possible on trivial grounds – like loss of feelings, or displeasure with your wife’s cooking. A law originally intended to safeguard the women of Israel was turned into an escape clause for self-indulgent men. In this example, Jesus is exposing the way the teachers of Israel have undercut God’s law prohibiting adultery by undercutting God’s laws prohibiting divorce (except under the narrowest of circumstances).
What this entire sermon on the law ultimately seeks to show through God’s holy perfect law is that evil does not begin in political agendas, religious heresies, international conflicts, terrorist organizations, or radical ideas of social behavior. It begins inside the hearts of all men! Neither does good begin in moral effort, self-sacrifice, religious performance, or social programs. Good begins only and always in the same place: the heart of God on display atop a Roman cross outside the walls of a Jewish city.
The last few weeks we have seen that an understanding of God’s law is a critical need for Christians today. The verses before us illustrate that point. Since Jesus gave the law, he knows what is in all men’s hearts (Jn. 2:25). He knows no human is free from temptation nor from the influence of indwelling sin (at least in this life).
TRADITIONAL STANDARD (27)
27 “You have heard that it was said, ‘You shall not commit adultery.’” As in the law against murder, this is a letter-for-letter rendering at the Greek version of the Old Testament’s 7th Commandment. It is a perfectly formed, sublime statement of God’s law. R.T. France, in his commentary, explains it this way:
It is concerned specifically with a man who has sexual relations with another man’s wife. The “woman” in Jesus’ declaration is thus to be understood also as another man’s wife … and the looking “in order to desire her” (literally) specifically of wanting (and planning?) sexual relations (hence my translation “wants to have sex with her” above). The focus is thus not (as some tender adolescent consciences have read it) on sexual attraction as such, but on the desire for (and perhaps the planning of) an illicit sexual liaison (cf. Exod 20:17, “you shall not covet your neighbor’s … wife,” where LXX uses the same verb, epithymeō).
It became easy for the teachers of the law to have a conveniently narrow definition of sexual sin. It was very simple and very clear. You’re either an adulterer or you were not. If you were caught practicing adultery, you were to be stoned to death. That made the law simple and convenient and deadly. People were able to look at this particular sin in a very black or white way. It was entirely binary: Sinner or not Sinner. Instead, Jesus communicates a radically new standard. It is in continuity with the Old Testament, but it supersedes it and completes it.
NEW STANDARD (28)
28 But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.
As we seek to understand what Jesus means, we need to know also what he does not mean. He does not mean it is wrong to look at a member of the opposite sex admiringly, but it is wrong to do so lustfully. He is not forbidding natural, normal attraction that is part of our humanity. What he forbids his turning another person into an idol: “I can only be happy if I make that person mine.”
The first look may be casual, but when the next looks become persistent, the desire is no longer momentary or involuntary but cherished. “I must have ____ in order to be happy.” Jesus’ language is expertly calculated. He uses a judicial form of speech that gives his pronouncement a final authoritative flavor. He uses the aorist tense which conveys the idea that the person has already committed adultery. The tense displays an accomplished, irreversible fact. It occurs in the very essence of the sinners being. the Infidelity begins in the heart and leaves one completely guilty whether acted upon or not.
Just as with his explanation of the law against murder, we all find ourselves adulterers by this standard. There is no room for relative morality and judgmentalism and pious condescension towards those who have fallen into sexual sins. His pronouncement of the law is meant to instill within us a poverty of spirit and a humility that realizes we are spiritually bankrupt and amazes us that God loves us with his unfailing covenant loyalty love.
Last week we mentioned how King David hatched a plan to have one of his soldiers murdered so that he could steal the man’s wife. There was no remission of sins for murder. The penalty was death. The same penalty was in place under the Mosaic law for adultery — the thing for which David became guilty before he ever sent for Bathsheba to be brought to his palace and before he ever hatched his murder plot (2 Sam. 11:1-4). No sin was ever committed that was not first imagined.
Our imagination distinguishes us from other animals and is one of God’s great gifts. With imagination, we dream great dreams. Without it there would be no great works of art or achievements of science. But, after man’s fall in the Garden, as with any of God’s gifts, our strengths have the capacity to become our weaknesses because there is no aspect of our human nature that is not tainted by our desire to act as our own gods.
The commandment against adultery involves the breach of several of God laws. It is disobedience to the specific command that forbids it. So, it involves disobedience to the Lord whom we are to worship. It also includes theft of another person’s companion. That arises from coveting what belongs to someone else. Its pleasure is ultimately that of serving an idle created by our desire to be our own gods.
Jesus does not pick the commandment against adultery because it is the second-most horrible thing one could do. First, he mentions it because it is a death penalty offense. Second, he mentions it because it is very unevenly applied and frequently overlooked by the priests. It’s kind of a hassle to stone people. Third, and perhaps most importantly, adultery is how God chooses to describe everything the people of Israel did in rebellion against him – particularly their political alliances with pagan nations, intermarrying with pagans, and the worship of demon gods and goddesses.
Just one example found in the prophets of this kind of adultery can be found in Jeremiah 18, where the prophet sings:
12 “But they say, ‘… We will follow our own plans, and will every one act according to the stubbornness of his evil heart.’ 13 “Therefore thus says the Lord: Ask among the nations, Who has heard the like of this? The virgin Israel has done a very horrible thing. …my people have forgotten me; they make offerings to false gods. 
The heart tugging story of Hosea is one long prophecy against Israel’s adultery with foreign nations and their gods. The Whore of Babylon in John’s Revelation is another illusion to all forms of idolatry as adultery. Jesus himself uses this imagery in condemning the leaders of Israel. Twice in Matthew and once in Mark, Jesus refers to Israel as “this wicked and adulterous generation” (Matt. 12:39; 16:4; Mk. 8:38).
Jesus is speaking to more than sexual purity. He is speaking of spiritual purity. That is the essence of the first commandment, “You shall have no other gods before me” (Ex. 20:3). Coveting anything, any person, any situation – certain that will make you “happy” – is committing adultery against God. Sexual fidelity is simply one category representing the Kingdom power of purity of heart.
How can we be confident Jesus is applying a broader principle than marital infidelity? The apostle Paul teaches that marriage is a metaphor of Christ’s relationship to his church:
25 Husbands, love your wives, as Christ loved the church and gave himself up for her, 26 that he might sanctify her, having cleansed her by the washing of water with the word, 27 so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish. 28 In the same way husbands should love their wives as their own bodies. He who loves his wife loves himself. 29 For no one ever hated his own flesh, but nourishes and cherishes it, just as Christ does the church, 30 because we are members of his body. 31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” 32 This mystery is profound, and I am saying that it refers to Christ and the church.
NEW DEMAND (29-30)
Jesus’ new and improved law comes with much more difficult and more strict demands. “29 If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. 30 And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell.”
This was one of Jesus’ favorite sayings. He used variations of it several times (cf. 18:8, 9). Some have taken Jesus’ words literally. One of the more famous cases was Origin of Alexandria who had himself castrated. Shortly afterward, the Council of Nicaea outlawed the practice. They knew that mutilation was contrary to scripture and that poor Origin still had his eyes. Even if his eyes were removed and his hands were cut off, he still had his mind’s eye.
Jesus is using radical language to warn us of the danger of indulging our idols. He is telling us that anything that stands between us and God must be ruthlessly torn out or cut off and thrown away. Drastic measures are always needed in order to protect our spiritual health. But if Jesus is not speaking literally, then exactly what drastic measures are we supposed to take?
We grow in our Christian lives through believing the gospel, by making it concrete. You might recall the crowds brought that question to Jesus and John 6. And his answer may surprise you. They asked what they should do to be doing the works that God requires. Jesus answered, “the work of God is this: to believe in the one he has sent” (Jn. 6:28-29). Jesus said the work that pleases God is to believe God. In other words, the Christian life is not about doing, it is about believing. That’s hard for us to take because we are all natural “doers.” Give us work. Challenge us. Tell us how to make ourselves better.
But what Jesus is preaching in this sermon is that our surface sins are only symptoms of a deeper problem. Under every sin we commit is an idol of the heart, a false god that has blinded us from the true God. Whatever good works we attempt to do must flow from our sure confidence in God’s favor.
And we must come to grips with the idols of our heart that are the sin beneath the visible, outward sin. Pick any sin of which you become aware and under it you will find an idol. There are numerous idols of the heart: the idol of approval; the idol of control; the idol of reputation; the idol of success; the idol of security; the idol of pleasure; the idol of knowledge; the idol of recognition; the idol of respect.
On and on goes our lists of false saviors that draw our attention away from God’s revelation promising that Christ is in control and that, in Him, we have a super abundance of approval, reputation, success, security, pleasure, knowledge, recognition, and respect. My problem is that I refuse God’s revelation and turn to my functional saviors to deliver what only the real Savior can deliver.
That means when we hear Jesus’ laws that point to the sin beneath the sin, we are free to dance, not beat ourselves up. We dance the Christian two-step: repenting of our deep heart idolatry, and believing, turning our minds toward, the gospel promises that alone break the power of our idols. Doing the work of God by believing him requires a continual rehearsing and delighting in the privileges that are ours in Christ. Repentance and faith are not steps on the path; They are the path. The work of God is to believe.
Only God offers an endless supply of covenant loyalty love for his constantly-adulterous people. Sometimes, if you are like me, you think God must get mighty sick of hearing you repent of stuff. Maybe you see him like one of your parents, throwing up his hands in frustration and exclaiming, “What am I gonna do with you?” But he sings over you in delight because your Christian two-step is his work in you.
So let’s end with hearing one of God’s many promises to his rebellious, adulterous child Israel:
3 the Lord appeared to [Israel] from far away. I have loved you with an everlasting love; therefore I have continued my faithfulness to you. 4 Again I will build you, and you shall be built, O virgin Israel! Again you shall adorn yourself with tambourines and shall go forth in the dance of the merrymakers. 5 Again you shall plant vineyards on the mountains of Samaria; the planters shall plant and shall enjoy the fruit. 6 For there shall be a day when watchmen will call in the hill country of Ephraim: ‘Arise, and let us go up to Zion to the Lord our God.’” 
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Mt 5:27–30.
 R. T. France, The Gospel of Matthew, The New International Commentary on the New Testament (Grand Rapids, MI: Wm. B. Eerdmans Publication Co., 2007), 177–178.
 Ferguson, 86.
 France, 204.
 Ferguson, 88.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Je 18:12–15.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Eph 5:25–32.
 Hughes, op. cit.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Je 31:3–6.