“You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.” (Matthew 5:27–28, ESV)
The word adultery means, literally, to mix seed.
In many ancient cultures, the sin of adultery could only be committed by the wife. In a time when bloodlines were guarded for reasons of nobility and the posterity’s “right to rule,” and DNA tests weren’t a thing, a married woman who copulated with a man other than her husband not only violated her covenant bonds, she jeopardized her family’s heritage.
When God separated a people unto himself and covenanted with them, he revealed the true standard, one just as serious, but more virtuous and equitable.
“If a man commits adultery with the wife of his neighbor, both the adulterer and the adulteress shall surely be put to death.” (Leviticus 20:10, ESV)
When God revealed Himself in the person of Jesus, He further clarified the full extent of the Law.
As it pertains to adultery, those involved are not condemned after committing the act. They are condemned even before–and without the physical participation in–the act.
Adultery is condemned at the moment there’s lustful intent in the heart.
The gospel teaches us that we are much worse than we first thought. But it also teaches us that we are more loved than we could ever imagine.
The same Jesus who knows and reveals the very intentions of our hearts took those sins to the cross, and in a physical act, suffered for them in our stead.