The notion of sin dominated my girlhood. Raised in Indiana by fundamentalist parents, sin was the inflexible yardstick by which I was measured. Actions, words, even thoughts weren’t safe from scrutiny. The list of sinful offenses seemed infinite: listening to secular music or watching secular television, saying “gosh” or “darn” or “jeez,” questioning authorities, envying a friend’s rainbow array of Izod shirts. God was a megaphone bleating in my head: “You’re bad, you’re bad, you’re bad!” I had recurring nightmares of malevolent winds tornado-ing through my bedroom — a metaphor, I now realize, for an invisible and vindictive god.

I had little contact with people outside of the rigid triangle of my Calvinist home, church and school. Weekends were busy with “Calvinette” activities, and later, “Young Calvinists.” I feared non-Christians in general and atheists in particular. Because unbelievers didn’t have the stick of eternal damnation hanging over their heads, they had no reason to act morally, and were therefore, I believed, capable of utter depravity.

But then, as a teenager, I started attending a public school and my black-and-white worldview started gaining color and nuance. I became good friends with a Jewish girl, surreptitiously listened to Casey Kasem’s “American Top 40,” and hid copies of Glamour magazine under my mattress as if they were pornography. I stopped fearing the secular world and grew intrigued by it. And paid the price: At 17, after being caught “fornicating” with my high school boyfriend, I was sent to a Christian reform school where children were beaten in the name of God. It was there that I learned that religion has nothing to do with goodness and there’s a strong link between zealotry and hypocrisy.

I lost my faith by fits and starts. The absolute truths of my girlhood crumbled when I watched Carl Sagan’s 13-part “Cosmos” series in graduate school — a program that included an overview of evolution which made it verboten for me as a kid, but whose logic made irrefutable sense to me as an adult.

But still. Religious brainwashing imposed from infancy is hard to shake, and I continued to confuse “Christian” with “trustworthy” and “moral.” When my husband and I contemplated having children, I wondered how I’d teach them right from wrong without a church. I toyed with the idea of dropping them off at a Sunday school, where they could ingest bite-sized chunks of morality in catchy songs and coloring books. But my husband — Catholic by culture, atheist by intellect — wanted nothing to do with organized religion.