Matthew 5:27-28
²⁷ “You have heard that it was said, ‘You shall not commit adultery.’ ²⁸ But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart (NIV)

I received this question:

“Matthew 5:28 seems to say the sin of adultery has been committed if a man lusts in his mind, yet he did not act upon it. But the Bible also teaches that temptation is not a sin unless we act on it. I am confused by this. Can you explain?”

This is a great question. I believe the confusion is about the translation from the original language combined with how words in the English language change over time as well.

In the NIV, the phrase is ‘anyone who looks at a woman lustfully.’

The KJV translates it as ‘whosoever looketh on a woman to lust after her.’

A current dictionary gives the definition of the word ‘lust’ as a strong desire, especially such a feeling driven by sexual arousal. However, the original word is epithymeō. This word has an element of the same definition as the current dictionary lists for the word ‘lust.’ However, it goes deeper into another word which is ‘covet.’ We see this in the ten commandments:

Exodus 20:17
¹⁷ “You shall not covet your neighbor’s house. You shall not covet your neighbor’s wife, or his male or female servant, his ox or donkey, or anything that belongs to your neighbor.” (NIV)

It’s not the exact same word as we saw in Matthew. The Old Testament was originally written in Hebrew but the words are strongly related which is why they are translated so closely the same. The word ‘covet’ we can see does not necessarily have the idea of sexual arousal as we think of the modern definition of ‘lust.’ According to the Old Testament, a person could lust even after a house, which would not be sexual in nature.

The word ‘covet’ means to long for something but with a deeper emotion that leads someone to feelings of anger when they don’t feel someone should have something nice. It can go further into feelings of jealousy where a person also wants what the other person has. For example, to covet a neighbor’s house, a person would not simply want a house similar to their neighbor’s, but they would want that specific house and it would be bothersome to them that their neighbor had that house.

In the passage in Matthew, the meaning is not simply that a man may look at a woman and consider her to be attractive. It would be more than a man being sexually aroused by another man’s wife. It would be a fit of jealousy for that woman. The heart would burn to possess her.

If we go deeper into the root word, it would also indicate indignation toward the one who had what we desired with a fierceness that would lead us to sacrifice other things in an attempt to take that thing or that wife away from our neighbor.

One more component to this word is found in the translation where, in the KJV, it says a man would ‘lust after her.’ This is an action toward taking from a neighbor as one’s own possession.

To lust in the context of Matthew 5, with a deeper understanding of the word translated as ‘lust,’ suggests that a man has a fierceness within him to steal away another man’s wife to the point of taking advantage of certain moments to accomplish this goal. It could mean thoughts are running through his mind of how he might make this happen.

If we read this word only in the context of the modern definition of the word ‘adultery,’ it can cause confusion exactly as the question suggested. It would seem that a person would be sinning if they noticed and were attracted to their beauty and form even if they did nothing to act on these thoughts of attraction. However, God has made us, men especially, to be attracted to the opposite sex by sight. This causes men to generally be the pursuers. This is God’s design. In Ephesians, Christ is compared to the groom, and we, the church, are His bride. This is to help us understand that He, as our groom, pursues us with the same intensity as a man would his wife in the honeymoon period. When we consider how men pursue a woman they are attracted to for the purpose of romance, it gives us a picture of how consumed God is with pursuing us and how much He desires a relationship with His creation.

This is part of God’s natural design and our attraction to the opposite sex does not disappear the moment we say I do. Our eyes are not suddenly covered with some mystical scale that makes all married women seem grotesque to look at. We have been created with sexual attraction.

However, when we don’t think our neighbor is worthy of his or her spouse but we are, we start scheming in our mind how to take them away. Sin is found when we allow our minds to stay focused on this person or thing in a covetous way. It is the obsession wrapped up in jealousy that leads to scheming even if our scheming is not a conscious choice. The sin of heart adultery lies in the choice of maintaining the focus of our desire on what is forbidden with a passion to take what doesn’t belong to us. This is more than simply noticing another’s beauty or being struck by how attractive they may seem.