The Unitarian church that my parents took me too (both of them, actually, the one in Washington State and the one in Ottawa, Canada) had a Sunday school, with classes divided by age. I remember reading a storybook about Buddhism, coloring, acting out stories from the Old Testament, etc. There was a class for slightly older children (I was maybe 11) and that was where I got my first book about puberty, and the grownup talk that came with it. I don't remember finding Sunday school incredibly fascinating, but I don't remember not wanting to go, either. (My brother hated it and his resistance was the main reason why we eventually stopped going, but he also hated skiing lessons, cottage trips, and pretty much all the activities we did as a family.)