I think some people somewhat overstate the idea that we will live in eternity and there is no time in heaven. Properly speaking, only God exists in eternity. Yes, the Bible and the Church talk of us having eternal life, but as Aquinas says, that is because there will be no end, but it is not the same as living in eternity. Eternity has no before and after, is incompatible with the concept of before and after. Aeviternity is how we will live in heaven, it is in between time and eternity. Angels and saints have a beginning. While Angels and our human souls are not changeable in their essence, they are changeable both accidentally and potentially. Angels can have a new revelation imparted on them, they are aware of the before and after states of this new revelation, that is change. Peter Kreeft says we will never stop learning in Heaven, that is change. Also, they have the potential to no longer exist (that is within God’s power), that is also change. This change in heaven is “measured” not in time but in Aeviternity. Aeviternity has a beginning, but no end. Eternity has no beginning or end. Before and after are compatible with aeviternity, but not with eternity.
As Peter Kreeft writes: “Eternity does not mean simply endless time; that would be boring. Nor does it mean something strictly timeless; that would be inhuman. Time is part of our consciousness, and God does not tear up his plan for us; rather, he fulfills and transforms it.” Note: Kreeft does not use the term Aeviternity, but reading his papers on Heaven it quickly becomes apparent that is what he refers.
Also, I have read, but cannot find the reference, that we will have work in heaven. Not toil, work. We were made to serve God and others, that what love is all about. That will not end. We will have bodies, there will be some material aspect to heaven, hence there will be change. Hence we will not be in eternity.
To me, its easier to envision eternity for God, than it is the aeviternity of angels and saints. Aeviternity allows for change, yet we will experience it as a whole. Even more difficult to understand, how does this fit in, precisely with material bodies? I have not found adequate answers.
Finally, I wonder if the damned will actually live in time, as opposed to aeviternity. Perhaps this is one of their sufferings.