At the end of my first-year lecture on evolutionary theory, I said that I didn’t believe in the theory of evolution – I accepted it as the best possible current explanation for for the enormous body of information we have about life’s diversity & relationships. One of my students was quite puzzled by this (at least, I hope it’s just one!) – how, they said, could I stand up there & teach them something I didn’t believe in?
This caused me to wonder about my teaching – perhaps I hadn’t explained myself as clearly as I might have done… But it also highlights the difference between science & what we might call ‘other ways of knowing’ about the world. Science simply isn’t a matter of blind faith (belief) – it’s evidence-based. And the data scientists gain is assessed for accuracy & relevance. If the weight of the evidence suggests that a re-think is necessary, then that’s what will happen. Nor are scientific theories cast in concrete – they are always subject to change if the evidence warrants this. And in fact they’re constantly undergoing rather rigorous testing – after all, if someone could conclusively demonstrate that the theory of evolution was not an accurate explanation, then that someone would be in line for a Nobel prize.
So that’s why I don’t ‘believe’ in evolution :-)

Interesting. When Rodney Hide refused to answer questions about global warming on that basis I thought he was just weaseling.
I think you’re being unfair on the word ‘believe’. All it means is that you think something is true.
Conversely, if you don’t believe it you either think it’s not true or have no personal opinion on the subject. The latter is probably a valid position for a scientist with regard to science, but I suspect it’s not common in terms of the general principles of a field.
The actual quality of the thinking behind a belief can be quantified with a wealth of adjectives: ‘rational belief’, ‘evidence-based belief’, ‘unsupported belief’, ‘dogmatic belief’ … which just goes to show ‘believe’ doesn’t, in itself, say anything about that thinking.