“You have heard that it was said, ‘You shall not commit adultery.’ But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart.” — Matthew 5:27-28 (NIV)
Marriage is about giving; adultery is about taking. This single sentence captures, with remarkable economy, the fundamental orientation reversal that adultery represents. Marriage, rightly understood and practised, is a covenant of self-giving, two people consistently offering their fidelity, their attention, their vulnerability, and their future to one another. Adultery inverts this entire posture. It is, at its core, an act of taking, extracting pleasure, validation, or escape from a connection that has no rightful claim on what is being given, while simultaneously stealing from the marriage covenant the exclusivity it was promised and depends upon.
This reframing matters because it locates the wrongness of adultery not merely in the breaking of a rule but in the violation of an entire relational orientation. Adultery breaks into the unity that two people have in marriage, an image worth sitting with. Marriage creates something genuinely new, a unity scripture elsewhere describes as two becoming one flesh, and adultery is not merely an individual moral failure committed in isolation; it is a breaking and entering into a unity that was never meant to admit a third party, however willing all parties involved might be in the moment.
Jesus’s extension of the seventh commandment in Matthew 5:27-28 is, for many readers, the most unsettling teaching in the entire Sermon on the Mount. Anyone who looks at a woman lustfully has already committed adultery with her in his heart. This does not collapse the moral distinction between lustful thought and physical infidelity into complete equivalence; the consequences and the relational damage of each are clearly different in scripture’s broader treatment of sin. What it does is refuse to let us locate adultery’s wrongness exclusively in the external act, insisting instead that the heart’s orientation matters as much as the body’s behaviour, because the heart is where every external act actually originates.
This teaching is uncomfortable precisely because it removes the easy refuge many people unconsciously rely on: the assumption that as long as a physical line has not been crossed, the heart’s wandering is essentially harmless, a private indulgence with no real moral weight. Jesus dismantles this refuge entirely. The heart that has already been giving itself away, in fantasy, in lingering attention, in the cultivation of desire for someone other than one’s spouse, has already begun the process of taking that adultery, in its fuller sense, ultimately completes.
Jesus’s accompanying instruction, that it would be better to gouge out an offending eye than to allow it to lead the whole body into hell, is deliberately hyperbolic, not a literal prescription for self-mutilation but a vivid illustration of just how seriously this matter ought to be taken. Drastic, decisive action, removing whatever specific input is feeding lustful patterns, cancelling certain channels, blocking certain content, ending certain relationships or interactions that have become compromising, is presented not as an overreaction but as the only response proportionate to what is actually at stake.
Today, examine honestly whether your heart’s orientation toward your marriage, or toward marriage in general if you are not yet married, is one of giving or one of taking. Where lustful patterns have been quietly cultivated, even without any physical line yet crossed, bring them honestly before God, and consider whether drastic, decisive action is required to interrupt them before they grow further.
Prayer
Father, examine the orientation of my heart, not just my actions. Where I have been taking rather than giving, where lust has quietly taken root even without any external line being crossed, expose it and help me address it decisively. Give me the courage to remove whatever is feeding the wrong desires, however costly that removal might feel. I want a heart that gives, the way you have given everything to me. In Jesus’ name, amen.
