I prefer not to have beliefs, I think it's limiting and lends itself to a kind of subtle (and sometimes not so subtle)arrogance.

Belief is essentially saying "This thing is an unknown, I nor anyone else really knows the answer, but what feels right to me is *insert belief*, and well i'm me, so i'm probably right"

I'd rather admit not knowing and speculate on possibilities.
When information and knowledge is forthcoming, then the unknown becomes known and conclusions based on facts can be drawn.

Speculation is, i feel, healthier and more imaginative than belief. It also lends itself to a constand search and discovery of the world, whereas belief can actually limit and close ones mind to possibilities.

Of course im using the word belief here in the "bigger sense", implied by the title. Not the everyday use for little things, where the word belief is used more as shorthand for "i think i know, but am not sure".