I come across many people that say God existed for an eternity before creation.
Putting aside all the problems coming from that idea. (time before time, eternity implies no end and so here we are, etc)
If God existed eternally before he made the universe, why did it take him so long?
Also, what did he exist in? Space is post-creation, as is time. A sequence of events must have happened before creation, right? So now he has no time.
Time is required to act (create) - Without it, God cannot do any action at all until he created time.
The Second Dimension is required to note changes in the First.
The Third Dimension is required to note changes in the First and Second.
The Fourth Dimension (which is Time) is required to note changes in the first Three (which are Height, Width, Depth, "Space", as you call it).
To note changes in a Fourth Dimension, mathematically speaking, one would need to exist in a Fifth Dimension.
To be capable of creating the Fourth Dimension, the creator would need to reside in a Fifth (or Higher) Dimension of existence.
With a Fifth Dimension, manipulation of the Fourth (which we call time) is possible.
Action in the First Dimension is only possible if one resides in the Second (or Higher). The same pattern is repeated upward, so a thing existing on a Fifth Dimension could manipulate the Fourth.
But the more satisfying way to put this is "wibbly wobbly, timey wimey."