Kendall's brings up a good point with his insight about eternity, re-incarnations and afterlife.
The problem I find is that people understand these concepts on some level but then get them mixed up on another level.
Spiritual concepts are important but at the same time we are human beings physically present on planet earth, where part of our job is to work on being grounded, centered and learn from dealing with the present reality you have been given.
Being alive is sacred, and not to be traded in because the afterlife is better or that we are going to return to it anyway so why not pack it in and go back now.
I like what Quinten Crisp had to say about this "why would I want to think about the afterlife when I am having enough difficulties dealing with this life."
Personally, I think I'd rather wait until my number was called.

Little Neo