If a so-called "faith" school accepts government money, it cannot refuse admittance to adherents of other faiths, or no faith. If a school accepts only fees from parents, and no government money, presumably it can set its own admission rules. Schools are still supposed to ensure that the correct curriculum is followed, but it still may not be. There have recently been cases of at least one jewish school refusing to teach sex education and some aspects of evolution, for instance.