In Ohio public schools during the 1920s, religious education was taught on a once-a-week basis. Each day began with a prayer and pledge of allegiance to the flag. Religious teachings were Protestant-oriented and most Catholic families sent their children to parochial schools. Problems of parochial schools surfaced when their students entered the public schools. More often than not these students were a grade behind and were stigmatized as a result.
Personally, I have no interest in religion except from an academic standpoint. I do enjoy studying the variety of religions and making comparisons. I believe my early public school introduction to religion was valuable from the standpoint of teaching moral values. I'm thankful for that and often find myself quoting from the Bible in that respect.
If I had my way, the schools would teach grade school children moral values. It could be done in a general way based on a composite of religious teachings. Or, a course in ethics. I find the lack of moral principles in today's society distressing.
How, or who created the universe is not nearly as important as how we conduct ourselves in it. My interpretation of church and state separation is that our Founders did not want one dogma forced on everyone at the federal level. Many of our forefathers settled here to escape religious atrocities in Europe. Let's not forget that.