What do I "believe?"  Ah that is the problem; I have opinions that change from time to time as I learn things, and some of which I act as though I believed, since I am highly confident of them, but I try very hard to "believe" nothing.  Belief is a pernicious thing -- it is a view of the world deeply embedded in the subconscious that people are not even aware of, but around which they base their lives, and which creates great unhappiness when it comes into doubt (both fear and guilt) as well as anger and resistance.

Opinions are a better thing entirely -- we have them on the surface and can examine them whenever needed and aren't attached to them nearly as much (only ego is involved with opinions while the very basis or our lives is involved with beliefs).