This verse—wonderful, grandly mysterious, and full of import—exceeds our comprehension because it is something beyond human experience. What does it mean to inhabit eternity? No human can adequately explain it, and we are humbled to realize from verses like this how insignificant we are beside the awesome grandeur of our God.
We can say that eternity sums up all of time—past, present, and future; it stretches endlessly in each direction from when we find ourselves living. But God inhabits, lives in, all of time! In contrast, we are aware of only a tiny fraction of the past and virtually ignorant of the future.
God knows beginning and end. In fact, since He knows the end from the beginning (Isaiah 46:10), He is in control of the entire timeline; otherwise, He could not know how things will end. In comparison, we know by experience that we are in control of so little. Events frequently do not work out as we hoped. What a difference there is between God and us!
Eternity, according to Webster's, means "time or existence without beginning or end." We have applied this term to endless time so we can "measure" and grasp it to a limited extent. We do this because time, to almost everyone, is very important. To us of all people, time should be extremely important. We need not be frantic about it, but we should be concerned about its proper use. Why? Because how we use it will determine whether we will join God in His eternal Kingdom.