In Letters to Malcolm, CS Lewis says, as we are finite, so time will always exist as progression with the past falling away behind us. Peter Kreeft seems to follow Lewis on most views and yet seems to suggest in both his books on Heaven, that time is more of a 'point' ('all swallowed up as one', if you will) rather than spread out. I find this most peculiar as he quotes Lewis whilst writing these chapters on time! Do I misunderstand Kreeft or Lewis? Or are they genuinely (for surely the first time ever!) on different sides of the debate here?
Whenever I have asked God about this question, a very simple analogy comes to mind of geometry. To begin, I was in a fellowship meeting once, and the question was asked of how God can be three in one. A word of wisdom was then shared where the woman who responded said, "He is not 1 + 1 + 1, but 1 x 1 x 1". God has three dimensions (Father, Son, and Holy Spirit), which are 1 squared, or a cube, if you'd like to visualize it.
It is God who defines and limits time. Think for example, of God's conversation with Job where he states that he is the one who puts limits on the sea and waves and has set the boundaries of where they begin and end on the shore (the sea representing the terrestrial world of experience, and the land representing the spiritual realm which emerges higher than the terrestrial). We are in this cube of time - the universe as we know it.
God, however, is also eternal, which means he is both inside and outside of time simultaneously. To that end, He is a sphere, an unending existence without time. Inside that sphere, is the cube that we call time. (For example, the figure of speech a "chunk of time" would nicely fit to explain my context). All light sources on earth emit light energy in a spherical dimension, reflecting on how God as light is spherical, if you'd like to visualize things. So in many ways, time is a point, per se. In other ways, as nothing within God can truly perish, neither can time. We, in uniting with God when all things are renewed, will experience both as He does. So in essence, both authors are correct.
To cap off this idea, the outer darkness Christ speaks of so many times, is the void outside of the sphere of God in which there is no light (understanding) to be found, the weeping and gnashing of teeth being men who weep in remorse for their new abode, the gnashing of teeth them futilely attempting chew on and understand how they got to where they are in the first place. Unfortunately, their hell is eternity never understanding why.