Not necessarily without evidence.
Well, I think what he may have mean is the the existance of a god cannot been proved or disproved to any conclusive degree. So an Atheist believes there is no god. I'd agree that you don't pratice atheism, but if you believe in God, you don't have to practice either. That's if you are a follower of a religion. I mean if someone were to believe in a higher power, but didn't worship it in anyway, they couldn't be said to practice anything.
That also applies to Santa, the tooth fairy, and the Greek gods. The point is, they don't need to be disproved to not be believed in; they need to be evidenced for there to be a reason to believe in them. Existential negatives are assumed until positives are evidenced. It's the rational way to live--do the opposite, and you'll immediately have to make an infinite number of assumptions, many of them mutually exclusive.

I never said theism implies practice. Religion implies practice. A religion is a belief system.


Yet each man kills the thing he loves--
By each let this be heard...
The coward does it with a kiss,
The brave man with a sword!