I was sitting in an airport when I heard a television news anchor announce that General David Petraeus had resigned as director of the U.S. Central Intelligence Agency because of an extramarital affair. Almost as troubling as the news itself though, was the reaction of a husband and wife sitting nearby. “Why did he have to resign?” asked the wife. “I don’t care if he had an affair. Do you?” “No,” replied the husband, “I don’t care.” Presumably, each would have reacted differently if it were their spouse who had the affair. But when it was someone they didn’t know personally, they reasoned, why should they care?

In the days that followed, a parade of pundits expressed similar dismay that a man would feel compelled to resign his job over an affair. Of course, the special circumstances surrounding someone dealing with high-level national security information made it especially important that Petraeus not violate his marriage vows. And resigning was the right thing for him to do. But more broadly, the widespread befuddlement about why infidelity matters should drive Christians to biblical reflection—because it does matter.

To start the reflection, here are ten biblical reasons why we should care when other people have affairs. Though some of the Scriptures cited refer specifically to adultery’s impact in Old Testament Israel or the New Testament Church, each has implications for contemporary society at large.

1. An affair tarnishes a precious illustration of the relationship between Christ and the Church (Ephesians 5:32).

2. It hurts both parties to commit an act that unites their souls at the deepest level with no intention to unite their lives in a corresponding covenant relationship (1 Corinthians 6:16).

3. An affair provides legitimate ground for the innocent partner to seek a divorce (Matthew 5:32), thus eroding the stable societal foundation that marriage provides.

4. Affairs ruin people’s careers. Taking away one’s honor and bringing ruin are just two of the many consequences of infidelity listed in the book of Proverbs (Proverbs 5:1-14)—consequences that can undermine years of diligent work.

5. Affairs result in God’s judgment on the participants (Hebrew 13:4).

6. Affairs set in motion harmful patterns that can affect multiple generations in a family. David’s chaotic family life after his affair with Bathsheba is a case in point (2 Samuel 11-24), for similar turmoil often strikes the families of today’s adulterers.

7. Affairs disqualify otherwise useful people from leadership in the Church (1 Timothy 3:2). As a test of character, the apostle Paul required deacons and pastors in a local church to be “the husband of one wife” (literally, a one-woman man). Though Paul’s standard was stated exclusively for the Church, marital infidelity may well indicate a character flaw that would disqualify a man or woman from some secular leadership roles as well.

8. When they occur among professing Christians, affairs diminish the Church’s power to change society and sully its reputation (1 Corinthians 5:1-12).

9. Adultery prevents people from experiencing the joy of personal fellowship with God, for only the “pure in heart” are blessed to “see God” (Matthew 5:8). After his affair, David cried out, “Restore to me the joy of your salvation” (Psalm 51:12).

10. Affairs rob the participants of pleasure that can only be known in the sexual union of a faithful husband and wife—a joy illustrated powerfully in the Song of Solomon.

May God grant us a renewed love for the institution of marriage so that other people’s infidelity bothers us once again.