Define a sin.
"You must have been thinking bad thoughts!" Sally called across the net when my ex-husband, Terry, hit a wild, careening shot. We laughed. As a high school tennis coach, Terry was a great tennis player.
Sally and Terry were raised Catholic. Both became atheists in their early 20s. "Once a Catholic, always guilty," they quipped.
I believe the Catholic concept of sin causes people to feel guilty and insecure.