Metaphysical beliefs or faith comes down to certain existence claims. It seems to matter a great deal whether you, or your 'self' exists or not, for example. The question can be answered either way, either way it corresponds to some kind of experience or frame for experience. If it makes a difference then you might wonder what that difference is and to whom. The 'existence' itself is only a way of trying to keep some order in the questions that can be asked, and indeed you would be better to wonder whether existence exists.