Do what thou wilt shall be the whole of the Law.
Yeah, I am going to add my two cents, having been a Christian prior to finding the Law of Thelema.
You see, I have heard this argument being on both sides of the fence and both times - it is a dishonest way of saying that just because you do not have the right to impose your religion on others in a way that can make them feel uncomfortable, that you are no longer allowed to pray in schools. Sorry, that just isn't true and I know this first hand because I was one of those Christian kids that wore a t-shirt saying something stupid like "Arrest me, I am praying in school" or something to that effect - while attending events and groups like Fellowship of Christian Athletes and See you at the Pole.
However, what I can agree with is not allowing the "team" to pray together prior to a game because it has the potential to alienate non-Christian students from an activity that is supposed to be secular. If you have a Muslim, Wiccan, Thelemite, Buddhist, etc. student on the team, they would feel uncomfortable with a Christian prayer. I am pretty sure the Christians wouldn't appreciate it if the Thelemite students wanted the team to perform Liber Resh vel Helios when the sun goes down or the Buddhists to meditate on the dharma before the game.
You have your right to practice your religion, you have the right to believe what you will. You do not have the right to push your religion on others and alienating others because of your religion.
Love is the Law, Love under Will.