Reading through The Screwtape Letters and The Great Divorce, I find Lewis's ideas of time and eternity absolutely fascinating.  While I'm not sure if this is exactly how God works eternity out, Lewis's ideas ring true to me.

He asserts that The Present is really the only thing that we truly experience and that it is the closest we will ever come to experiencing eternity while we are bound by time in this life.  It makes sense.  Our ideas of Past and Future are really just that.  We obviously have experienced the Past, but our experiencing of it occurred in the what-was-then-Present just as our reminiscing of it occurs in the current Present.  Likewise, we will experience the Future, but it will then be our then-Present and any of the worries, hopes, or dreams of the Future that we entertain now are being experienced now.  Any energy wasted in anxiety of a Future that in a large degree is quite unpredictable is lost Present.

The most interesting application of this is that there is no such thing as a small decision.  Because Eternity is the ever-present Present, every choice that we make is the choice.  Which means that any failure on our part to do the right at any given moment is changing our course for Eternity.  We're all going to make honest mistakes.  It's part of our growth and just a part of life on Earth.  But we all know that not every mistake is unintentional.  Each of us have our own foibles, challenges, weaknesses, and guilty pleasures.  If we look at each choice as the important one it is, it can help us to choose correctly.  Viewing the Present as Eternity helps us to see that there really isn't any repenting to be done later.  The time for that is now.  Hopefully we'll have grown and changed by the time the future comes, but there really isn't any undoing what we've done now.  Of course we could delay our repentance and that repentance is always available.  We have that agency and that gift.  But any delay is going to retard the growing and changing we were looking forward to.

Now is the time to act.  Now is the time to choose.  Now is the time to declare whose side you are on.  Any dwelling on the past or delaying or worrying about the future is lost Present.  Just live life, choose wisely, and be happy.  It's meant to be that way.