File this under “stuff you should know” — If you visit the Petrified Forest National Park in Arizona, it’s highly frowned upon to take home pieces of petrified wood — and it’s illegal. However, that doesn’t stop people from doing it. Evidently, they’re not aware that these contraband souvenirs are cursed.

As far back as the 1930s, people who pocketed these pieces of wood-turned-to-stone have reported that their sticky fingers have resulted in bad luck. Many, even decades after their thievery, end up returning the wood pieces, often with what the park people call “conscience letters” — apologies and pleas for forgiveness — and also pleas to have the curse removed from their lives. You can read some of the letters online at www.badluckhotrocks.com.

One of my favorites: “To: The Keeper of Rocks. Adolescent foolishness caused me to take this. Adult guilt caused me to return this. In reality there are no excuses. Please forgive. Signed, Earth Lover.” Another one from 1983: “Please put this back so my husband can get well. I tried to keep him from taking it. — Distraught Wife of Sacramento, CA.” Someone named “Mrs. P.” confessed that she hoped her confession would save her marriage — her husband found the three rocks she had taken “hidden in my brassiere.” “Since then, being a true Christian, he has constantly told me of my wrongdoing,” she writes. “I’m afraid that our marriage is on the rocks,” adding that she was only returning two rocks and keeping one “to remind me of the lesson I learned the hard way.”

But she did enclose 20 cents “for you to buy another rock to replace the one I am keeping as a token of my guilt.” A token of my guilt. That phrase hits a nerve, doesn’t it? Because, don’t we all at times try to hold onto our guilt? I think we like the idea of penance, of self-punishment, self-abasement, self-mortification. We like confessing and re-confessing and devising ways of bettering ourselves morally and spiritually.

We also like holding onto our tokens of guilt. I’m sure there’s a dark, twisted psychological reason why and probably has a name for it, maybe even a diagnosis for it in the “Diagnostic and Statistical Manual of Mental Disorder” (DSM). Probably the most simple reason is that there’s something in us that doesn’t fully trust that if God says he’s forgiven us, he means it.

He has removed our sins “as far from us as the east is from the west” (Psalm 103:12) and reminds us that “there is therefore no condemnation for those who are in Christ Jesus” (Romans 8:1).

It’s a good thing to return rocks that we’ve stolen and send letters of conscience. We should ask for forgiveness of people we’ve sinned against and make amends and reparations and restitution. But when it comes to our relationship breach with God, Jesus said from the cross, “It is finished.” He bridged the gap, paid the price. He removed sin’s curse. If God says you’re forgiven, then you’re forgiven — believe it. And don’t steal rocks.

Nancy Kennedy is the author of “Move Over, Victoria — I Know the Real Secret,” “Girl on a Swing” and “Lipstick Grace.” She can be reached at 352-564-2927 or via email at nkennedy@chronicleonline.com.