I learned in youth group that HIV is small enough to slip through most condoms, and that girls can contract chlamydia by wearing a too-short skirt sitting on the wrong chair. These lessons followed in the tradition of the other church-based science I had received: from Sunday School, that girls have one fewer rib than boys; from a six-week Creation series, that a shrinking sun and the salt content of the ocean prove an 8,000-year-old earth. Most of these instructors were volunteers. No one monitored their lessons’ accuracy or measured their students’ learning. If a Sunday School teacher or small group leader got the facts wrong, well, at least they had a heart for teaching God’s word. And all of them usually still stuck the landing: love Jesus, believe the Bible, and don’t have sex.