But God warns us against those who would call evil good (Isaiah 5:20), and fidelity to your marriage vow is good. Thou shalt not commit adultery, God says. These are not the words of a conservative prig but they are the words of a generous God whose commandments are not burdensome but wise and good, and even those who do not follow Jesus understand this wisdom by way of their own irrevocable experiences.

I saw a billboard on the way to the airport that read:  Thou shalt not commit adultery. It advertised a website that specialized in extra-marital sexual connections for those interested in a little cheating.

I am speechless.

Perhaps I am a prudish, self-righteous Bible thumper mired in some version of an old Christian America that is fading away. So I will let someone else speak.

Wendy Plump wrote “A Roomful of Yearning and Regret,” published December 9, 2010. It appears on-line at the New York Times and I recommend you read it. She has been on both ends of adultery—perpetrator and victim—and reminds us that both bring agony. She writes:

I know this for two reasons: No. 1, I have had an affair; No. 2, I have been the victim of one. When you unfurl these two experiences in the sunlight for comparison, and measure their worth and pain, the former is only marginally better than the latter. And both, frankly, are awful.

Wendy goes on to say that though both are awful, the adulterous sex is great—in the raw hormonal sense. It is forbidden, new, urgent, and you can take on a new exciting persona. And, yes, of course you were bored, your needs were not met by your spouse, and your new lover really understood you. Every adulterer, she says, has said words like these.

As Christians we might wince when we read this, but there is hard-earned wisdom in what she is saying. There is pleasure in sin for a season. To gloss over that observation is to leave us unprepared for temptations. Sin can feel good. It kills us, but it feels good. And since it has its appeal, we must start our defense long before the temptation gets close.

Even Wendy offers help here. She confronts the common excuses for giving in to this temptation. “So what?” she says. “Does the argument that adultery makes you temporarily feel alive legitimize the foolish act? Absolutely not.” To which we might add, “unless you are an animal,” which is how sin debases us.

After Ms. Plump’s insightful words, we could listen to an endless line of victims and perpetrators, and we would hear many regrets and “awfuls.” Some remain married, though the marriage has days where there is a noticeable limp. Others have divorced and have not spoken to their children in years.

Sadly, these “awful” stories will not turn the foolish away from adultery and the billboard I saw may turn them towards it.  When we are foolish, we look for a co-conspirator to authorize our foolishness, and are easily baited by anything that calls bad desires good.

But God warns us against those who would call evil good (Isaiah 5:20), and fidelity to your marriage vow is good. Thou shalt not commit adultery, God says. These are not the words of a conservative prig but they are the words of a generous God whose commandments are not burdensome but wise and good, and even those who do not follow Jesus understand this wisdom by way of their own irrevocable experiences.

Ed Welch is a counselor and faculty member at CCEF. This article first appeared at the CCEF Blog and is used with permission.