I think a problem arises from those individuals who wear the badge of "Believer" and imagine that those who differ must also wear a badge such as "Atheist" or "Agnostic" and similarly fraternise at their own meetings. Of course it's nothing like this. Personally I am without the knowledge of or need for a god, so I think of my self as simply being atheist, as opposed to being an atheist. (Is this too subtle?)
Anyway as for giving up belief in the God of the Bible, I first gave up a belief in the devil because he is a ridiculous characterisation of all that is bad. In fact I pioneered not believing in the devil alias Satan and told other JWs I thought he was just a personification --and nobody complained! So I started doubting all spirit creatures.
Reading philosophy gave me an insight into spotting logical errors and made me realise that truth has to be consistent with evidence and reason-- and there is no concrete evidence for spirits. Then again the God of the Bible is a perfect tyrant. I remember the very moment I became atheist. I was standing, so I sat down and considered the consequences; it meant no more religion let alone no longer remaining a JW.
The relief was enormous, no longer imagining some unknowable and fiendishly powerful busybody permanently breathing down my neck-- and that joy continues!