A friend of mine left his wife and three children. Although he knows better—he was a seminary professor—he continues to lie to his family and is filing for divorce. Another friend abuses her family. She wastes their grocery money on her own wants, and then swears and screams when their bank account runs dry. Both of these friends are behaving irrationally, perhaps because both are guilty of unrepentant and repeated adultery.

There is something about sexual sin that ruins the minds of previously healthy people. Paul explains in Romans 1:18-32 that as people persist in sin, things can swiftly degenerate into a laundry list of “greed, hate, envy, murder, quarreling, deception, malicious behavior, and gossip.” Such people “are backstabbers, haters of God, insolent, proud, and boastful. They invent new ways of sinning” (Romans 1:29-30).

Like all sin, a person who engages in sexual immorality is opening the door to other dark decisions. Consider that everyone knows sexual immorality is wrong. Everyone knows it’s wrong to break their marriage vows or lust after another person—turning him or her into an object for their own gratification. Even people who claim to have no qualms about extramarital sex still describe their exploits as “being naughty.”

Sexual sin undeniably abuses another person for our own advantage. We know it’s wrong to dehumanize them, but our selfish urges are so strong that we just don’t care. And once we have committed such a blatantly selfish act, what won’t we do? Other sins can come easily for those who have already given in to lust.

Lust is a dead canary in the coal mine, the first sign that something has gone haywire in our walk with Jesus. Don’t make light of this sin. Repent before you do something really dumb.

NLT 365-day reading plan passage for today: Genesis 44:1-34