Thanks Jamie, I really appreciate your reply. I think you are probably right - that I have made a decision already to come out to my parents but am in need of some reassurance. That said, I've 'made up my mind' a few times before and still not summoned the courage to act...
I was interested to read your hypothetical comments from people objecting to the manner in which someone comes out. It made me realise that, almost subconsciously, I've been marshalling my responses to objections like this for when I tell my other brother. (He lives very close to my parents and I want to give him fair warning of what I intend to do, as he might have to deal with the fallout.) But somehow, I know I think that my brother should just deal with it - like, he's a grown-up, and he won't even have any religious objections, he can take it. It's almost as if I'm treating my parents like children though, wanting to shelter them. Weird.
I've been particularly struck by what you wrote about letting go of the results of my coming out, because I have no control over them. (It reminded me of something a good friend of mine once said about coming out being like making a bungee jump...). I think that is the scariest aspect by far. But from my parents' perspective, the consequences are in God's hands.
Thanks again, the replies I've received so far have given me a lot to think about. I'll let you know how it goes if and when I finally make the bungee jump.