After a certain point in life, it becomes necessary to determine how you want to live your life or the purpose for your time on earth.
Society has come up with a decent solution to occupy ourselves viz. to get married, have kids, support family. The 'responsibility' that it brings lends itself to a purpose for a major portion of life until you retire. And then you begin to ask the old nagging question. Have I really lived my life?
So, we amuse ourselves with friends and relatives, the television and the latest time sink: facebook.
If you believe in evolution, then it is clear that we really do not have any moral purpose in life. The brain is really a bag of chemicals which can be influenced to change one's behavior and the concept of 'free will' itself is being questioned because it turns out that most of the time, we are not rational. We only rationalize the decision we have already made.
On one hand, I really hope there is a larger, spiritual meaning to our existence. Not having any would mean that whatever we do is pointless. Really. It wouldn't make any difference if you are a man of values or not.
But on the other hand, I do not like someone watching over my shoulder. My choices should not be based on the fear of a repercussion by 'God'.
Is that why we do not know the answer to the God question?
For the sake of argument, lets assume that there is no God. What would our ideals be then?
I think the answer is evolution. Or, supporting evolution. To be better, stronger and faster as a species.
To question our situation or the way we do things now and find better ways to do it. To improve the standard of living.
If a person has done that then I think he has lived his life.