What are the disadvantages of wearing symbols that show your religion?

A possible disadvantage of wearing symbols that show your religion, is that some people are intolerant of religions other than their own, so you may encounter some hostility (that also depends upon what your religion is, and where you live). Of course the opposite effect can happen as well; you could encounter people who will like you more, because they see evidence that you belong to the same religion that they do. There are also some settings, such as a public school, which are supposed to be religiously neutral, and equally accepting of all religions, therefore any attempt to advertise or promote a particular religion would be considered inappropriate. But if you go to a Catholic school, then of course symbols of Catholicism are welcome.