In the US, everyone is allowed to believe what they will. School children are allowed to assemble in religious groups if they so choose, and pray all they want on their own time on campus. The school itself is not allowed to conduct religious ceremonies or endorse any particular religion in its official capacity. Teachers and administrators can, of course, believe whatever they wish, but cannot use their position or class time to push that belief on children, or to hold prayers, or what have you.