Aquinas's 'first way', which is based on what seem to be unavoidable truths about things that change (i.e.: everything but God), leads to the inescapable conclusion (IF you get on the particular thought train) that God is outside of time altogether.
For the purposes of mind-boggling, I like Aslan's saying (in The Voyage of the Dawn Treader), "I call all times soon," because the term soon has such a dynamic aspect that it works against thinking of eternity as merely static.
I mean this: When people object to the idea of a " merely personal" God, they usually end up imagining something LESS than personal. Similarly, when people (rightly, IMHO) object to the idea of a "merely temporal" God, they end up thinking of something in stasis, like a beautiful diamond. Just as the joy of Heaven MUST be better than we can imagine, so the eternity of God must be more than we can comprehend. I think we HAVE to think it, but, like the Trinity, we can't really understand what it is we have to think.
As a kind of metaphor, I think the n-dimensional image is very helpful.
Nevertheless, I worship and glorify Him as He is, not as I think Him to be.