We are so limited. We live in time, and cannot understand fully a God who does not, and is not constrained by it - He created it.
He is outside of it, and sees the beginning from the end.
There will come a “time” when “time” no longer exists for us, I believe. Eternity is not unlimited time, it is not made of time - it just IS.
We have no idea how to even think or speak of God's world or worlds beyond our own.
"It just IS" is a statement of unbelievable arrogance (apologies).
If a man blind from birth cannot comprehend what it is to see, how can we comprehend anything beyond that perceived by our senses and our tiny, self-consumed minds?
Whatever eternity (i.e. God's world) is...is so incredibly beyond our capacity to imagine that all we can do is express humility at the prospects of touching just a fleeting corner of it.