The Government isn't officially affiliated with any religion, but them and nearly all of america is a protestant christian. All but one of our presidents has been a protestant, and even the one who wasn't was still christian (catholic) and manged to cause a conspiracy of being controlled by the Pope. Honestly, what points is there to teaching religion in school? If a parent wants their child to learn about some religion, it's probobly their religion, so they or other, higher standing, members of their religion can teach it. If we were to teach any religion in school, we'd have to teach all of them for the same amount of time. That could be a day, a week, or more for every religion in existance. That's a lot of weeks. That could easily take up years of schooling. That's why it isn't taught in public school. There are plenty of college courses on religion and philosophy that any child can choose to take, and again, they could always just go to the relgion itself and ask to be taught its mantra.