For the God part, I just wish I was more tactful just because I know some people find it highly offensive. So at the least I could have been empathic to it by saying "I know this feels terrible to hear".

I like to go with the Gelfand principle: when introducing a new concept, give the simplest nontrivial example. Bringing up religion has the risk of offending people, sure, but it seems to me that the deeper issue is that the existence of God is a thorny metaphysical problem and it didn't appear clear to the audience how to apply the methods. It's got one hell of an impact though.