We have a number of interesting perspectives on the issue of time in here.
My take on this topic is that time is how consciousness experiences reality.
If there was no framework of time at all, then we would all experience the past, present, and future simultaneously. We do not.
Which is why past lives are in the past.
Sure, we can tune into vivid memories of former lifetimes and the Interlife (or period in-between incarnations) in mystical experiences related
to meditation and channeling, but that is not the same thing as actually being there.
Our past (i.e., this particular time-line) cannot be changed one iota, the present can be altered depending on our actions and inactions, and there
are possible futures as well as probable futures.
Change the present and you change the future.
Granted, if it were possible to travel faster than the speed of light for time travel, would it also be possible to venture into one or more parallel
time-lines in the distant past?
I believe so.
But is it possible to venture into a future that has yet to exist?
I highly doubt it, as there would be no where to go
To sum up, time exists but only for us to experience reality, as that is its purpose.
[edit on 21-3-2007 by Paul_Richard]