Recent post to a URC blog where, yet again, Christians with their backs to the wall are defending the 'existence' of God :
The use of the word 'exist' creates more heat than light. It's fairly clear to me that God doesn't "exist". The universe exists. God is a word we use for "that which is the reason anything exists at all" and "which holds it in existence". The trouble with arguing that God "exists" is that God then has to be some sort of super-existing being - more powerful, more knowing etc - and all too often ends up being modelled on human images of super-existence. Which tend to become oppressive. That's why the crucified Christ is so key.
Trinity makes sense to me as God-that-doesn't-exist / God-in-human-expression / God that enables humans to recognise the one in the other.
Religion is extremely dangerous and extremely justice-and-peace-making. It is extremely beautiful and extremely ugly. Extremely damaging and extremely healing. That's one reason why organised/institutional religion must be separated from the State (which has the monopoly on the use of force). However, the religious instinct is, I believe, hard-wired into human beings. If we don't worship God (who doesn't exist) we will worship Mars (power of force), or Mammon, or Aphrodite or something else that clearly does. As Walter Wink writes, if we worship these real but invisible forces, they will lead us off into the dark.
The religious instinct tends to lead people to cluster or coagulate around communal religious myths and (eventually) institutional structures - it's never just a private matter. Organised religion is an inevitability. The idea that religion can be eliminated is fatuous.
Precisely because it is so dangerous - and potentially beautiful - it must be done well. It can only be 'done well' from the inside - legal constraints (ultimately, persecution) from outside government that isn't religious can only go so far.
All the energy expended by people arguing that God doesn't 'exist' is largely wasted, because God doesn't (or does, depending what you mean). A better discussion might be whether God is present or absent, whether God speaks or has finished speaking. A religion is more like a language than a set of propositions (let alone an organisation). The best way to get constructive, healing religion rather than destructive religion, is to use the language and argue for it from the inside, grounding it in the truth - which includes the truths that science is revealing. Good religion can adapt to new truths - the world religions wouldn't have survived for millennia if they hadn't got the inbuilt ability to adapt.