The beauty of repenting from our sinful desires is that we start to attack the corruption of concupiscence when it first rears its ugly head. We don’t give our sin a head-start until it brings us fully under its control, but we ask God to forgive us, and then to begin his work of putting that sin to death, even as he causes his holiness to grow in our heart. Yes, concupiscent desires are already a violation of the Seventh Commandment; however, it is far more heinous to allow those desires to keep growing to the point that they are “not only conceived in the heart,” but they fester until they “[break] forth in words and actions” (WLC 151.3).

In the Sermon on the Mount, Jesus offers his authoritative teaching on the law. Through this section, we find Jesus arguing against the legalism of the scribes and the Pharisees—that is, the legalism that relaxed the infinitely high standards of the law (Matt. 5:19–20):

After showing that the Sixth Commandment against murder forbids even anger at our brothers (Matt. 5:21–26), Jesus begins teaching about the true requirements of the Seventh Commandment against adultery. Similarly, Jesus criticizes the traditional teaching of the rabbis that restricted the requirements of the Seventh Commandment to forbid physical adultery alone.

Much more, Jesus insists that the Seventh Commandment requires “pure and holy affections of the heart.”1 That God forbids coveting our neighbor’s wife should have been clear from the Tenth Commandment (Ex. 20:17; Deut. 5:21).2 What Jesus intends to demonstrate, however, is that even the Seventh Commandment by itself deals with these questions of the heart.3

Result or Purpose?

Against a minimalistic view of the Seventh Commandment, Jesus says, “But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart” (Matt. 5:28). To understand the weight of Jesus’ words, we must ask an important question about the grammar of this sentence: is the lust the purpose of the looking, or the result of the looking? That is, does Jesus speak against the man’s lust when it is his purpose/intention for looking, or is Jesus talking about the lust that arises as a result from looking?

Looking with Lustful Intent?

Here, many (most?) commentators take the former sense of purpose, which is captured in the ESV’s translation of the verse: “everyone who looks at a woman with lustful intent…”).4 According to this view of purpose, Jesus is condemning the man’s intentional, willful, volitional decision toward lust.

Lust Arising Unintentionally, Apart from Choice?

Two important technical resources, however, argue for the latter sense of result, rather than purpose. The first resource is Murray J. Harris’s widely renowned Prepositions and Theology in the Greek New Testament classifies this as a result, rather than purpose, citing a similar use of πρός (pros) to describe result in John 11:4: “This illness does not lead to [πρός] death.”5 The second resource is the standard New Testament Greek lexicon, by Bauer, Danker, Arndt, and Gingrich (BDAG), which classifies this phrase as “of the result that follows a set of circumstances (so that),” and translates the phrase as “one who looks at a woman with sinful desire.”6

According to this view of result, Jesus is condemning the lust itself that arises from looking on a woman—even when that lust arises unintentionally, and without any conscious decision of the will.

Matthew 5:28 in the Context of the Sermon on the Mount

How do we choose between the two interpretive options? To begin, we must consider the context of this passage. In the immediate context of the Sermon on the Mount, Jesus is revealing the full scope of the requirements of the law—requirements that go much further than we realize. So, Jesus taught that anger alone violates the Sixth Commandment (Matt. 5:22), and there is absolutely nothing in the text to suggest that this anger would be a conscious, volitional choice.

The immediate context, then, strongly suggests that Jesus is not only condemning clear, deliberate, willful choices to lust, but also (as with anger) instantaneous reactions of lust that arise from looking at someone who is not our spouse. So, it is not only a violation of the Seventh Commandment to commit physical adultery, and not only a violation when we deliberately stoke lust in our hearts, although both of those would be included.

Beyond that, Jesus is saying that any sexual desire toward someone who is not our spouse is already the sin of adultery—adultery of the heart. So, take a man who is minding his own business, but who happens to look up and sees a woman. If that man begins to experience unbidden, unchosen, and undesired sexual desires toward her rising in his heart, then that man has already sinned.

This, of course, is a heavy standard. How can we justify such a strict view of the the requirements of the law?

To understand the grounds on which Jesus condemns even unintentional lust, we must understand what theologians call the doctrine of concupiscence. Concupiscence is the Latin word for (sinful) desire or lust (concupiscentia), and, in the Latin Vulgate translation of the Bible, this is the word that translates this key phrase in our passage: “ad concupiscendum eam” (“unto desiring/lusting after her”). This is also the Latin word that translates the word for “covet” in the Tenth Commandment (“Non concupisces…” [“You shall not covet…”]; Ex. 20:17; Deut. 5:21).

Thus, concupiscence describes sinful desires, or desires that incline toward sin. The question that theologians have debated for centuries has to do with whether concupiscence is in itself is sin, or whether concupiscence does not become sin until the will consents to the sin that concupiscence desires.

Read More