Okay, first of all, there is no "separation of church and state". That phrase was taken from a Thomas Jefferson letter, where he promised that the government would not infringe on the rights of a church (kind of the opposite of how DUmmies want to apply it).
Secondly, lets look at the phrase "freedom of religion." When freedom of speech is applied, it means that people have the right to say what they please, not that people are protected from hearing speech they disagree with. Freedom of press means that the press can print what it pleases, not the people are protected from exposure to newspapers they dislike. Therefore, it would stand to reason, that freedom of religion means that people can practice whatever religion they so choose, not that people are protected from exposure to religions that they do not belong to.
Why is this so difficult to understand?