What, Teribus, no bishops voting in the Lords? When did the Lords Spirituous lose their vote?
I can see the argument for teaching about other people's beliefs, which might be no bad thing if done from a neutral point of view, which unfortunately is highly unlikely. But it's utterly wrong to give children the impression that religion has a monopoly of morality and other non- material (with a small m) considerations, and the simple fact is that in England at least, the Christian religion has a legal position which other beliefs do not. This is purely as a result of history rather than any intrinsic value of Christianity.
There's no doubt that public opinion would back Christianity in opposition to Islam or Hinduism. But that's because of the "soft" racism of the majority, coupled with the probability of a foaming display from the tabloids.