MaF:
Sorry for the headache. Actually Lacan didn't mean his "teaching" to be read, he gave most of it orally in his "seminaries". However the latter were eventually handed down in transcripts, and he also left a number of interesting writings (Ecrits) which are admittedly a difficult read. I had to get through some dozen of pages with less than half-understanding before I became used to his very peculiar style, and I found it fascinating in the end (which still doesn't prove that I understood it correctly).
Interesting. I can't quite see why it has to be non-existent, as opposed to merely inherently unknowable. In fact, if it must be non-existent, then it can only be a human construct or artifact, and wouldn't that defeat the purpose?
As poppers pointed out very well, any concept is a linguistical (i.e. human) construction. Acknowledging that means barring the concept as soon as you build it. Whence the importance of negation IMO, even though "no" is never the last word on anything.
An existent God would be just another part of reality, leaving it as a closed whole just as in positivist rationalism. Realizing that was a big step out of the WT (and of any full-fledged belief) in my case. Our ever self-enclosing, imaginary, "reality" needs to be splitted again and again, by unexpected happenings, by the experience of the Other in other people, but always through language.
I would love to use the word "God" as a metaphor, but I find this impossible as long as some people take it "for real". It can be done in some European circles, from the discussions on this board I feel it doesn't suit the US context, where you have to take sides as a "believer" or "unbeliever". The Greek deities like Venus or Apollo became available as metaphors when nobody believed they were "for real" anymore.