The scariest aspect of the future is its unpredictability.
I know that's what frightens me the most; there are more variables at play than I can account for, yet I must make a decision. I have to place a bet on one decision, one plan, and hope that the variables fall into place to make it more or less happen. I can't predict that my decision will result in what I want, but I can try to make it more likely. My decision could have unexpected or even undesired consequences, and I might end up discovering what I wanted wasn't really what I wanted. I might even realize that I want my life going a completely different direction after all.
The obsession with prophecies such as Nostradamus or the current concern over the end of the Mayan calendar in 2012 speaks to our desire for certainty, even if it is morbid apocalyptic certainty. It's almost comforting to think that the universe will perish in fire and destruction (especially if something supernatural or divine is behind it all, something beyond scientific exploration) instead of the universe expiring as the last star dies in the sky to leave a cold, lifeless universe. The universe should at least have the sense to die in a rain of sparks and collapsing stars!
It's as if there's some cosmic clock, ticking down the final millenia/years/seconds left, then BOOM! end of creation. It creates a sense of urgency; what I do today has to make the best use of my limited time.
On the one hand, it could encourage us to use what little time we have well. Maybe a perspective that makes us realize how little time we have could get us as individuals and as a species to work together for peace and justice.
Or it could put undue pressure on the moment. If I don't make the best use of this moment, then I've wasted it. Life could be like a summer vacation packed with all sorts of "fantastic memories" of family vacations to exotic locales, a childhood filled with non-stop sports and activities, or a car trip spent switching the radio stations just in case that one song you really want to hear in that moment comes on one of the other stations.
Right now I'm re-evaluating my life plans. It needed to happen, and it's a good thing. It's exciting to see new possibilities that I hadn't thought of. In order to do it, though, I have to accept the fact that the future's open-ended. I can't live in the shadow of some cosmic clock waiting to destroy everything I've worked for, and I can't live in the fear that I'm making a huge mistake that will waste the little time I have.
The message in the book of Revelation is that at the end, all of creation is in God's hand. Human history is part of God's story, too. It doesn't have to be perfect. It doesn't have to make the absolute best use of what little time we have (especially since it can't, because there are too many things going on for us to understand them all). God will exalt our good, will cleanse our sins, and all things will again be put right. While we have to make the best use of our talents and time now, we don't have to be perfect.
And the unpredictable future might still be scary, but it's also an adventure.