Due to the lay (untrained) instructors and the need to simplify the history and values sufficiently so that children understand, observing the value set thus promoted can be particularly insightful in understanding the belief system of a religious group.
Interesting definition... the phrase "sunday school" is often used to mean terribly nice and genteel. For the record I taught 5-7 years olds in Sunday school about 15 years ago and in common with many other churches we just followed a standard syllabus sent out by the Scripture Union. Consequently I am not sure the insightful comments were really that true either. --AndrewCates