One way of formulating it would be: "There is(are) no all-powerful supernatural entity(ies) which has(ve) influence over my daily life."
No one has given me sufficient evidence that would go against this and contradict the null hypothesis, so I continue to not believe in God(s).
That said,
I don't think that believing things that are not scientifically proven/provable disqualifies one from performing scientific research. I'm know I have plenty of opinions/beliefs/biases that I couldn't back up for the life of me. It is part of being human and having been raised in a given environment. But it is important to be aware of your own biases in any endeavor.
I think agnosticism would be the better choice for a null hypothesis.
http://en.wikipedia.org/wiki/Albert_Einstein%27s_religious_v...