Blood Donation. Why?

On Father’s Day, I went with my wife to an event organized by the Read Cross, to honour those who have given blood 25 times, or its multiples.  It turned out there were ~2,500 people who have given 25 times in HK, like me.  In fact, I have given 10+ times in USA, and another 10+ times in Canada.  So I have given roughly 50 times in total, just about enough to qualify for the next step up.  I looked around, and we were all sorts: old, young, men, women, well-dressed, casually-dressed, trendy, old-fashioned - quite a cross section of HK. 

It was a nice gesture of the Red Cross.  However, we certainly did not let them stick a needle in us to take 500 CC of our blood, 25 times, just to get a nice lunch, a small towel folded in the shape of a wine bottle, and a pin.  So why did we do it?  For the satisfaction that someone who lost a lot of blood through surgery, child birth, ulcers, internal bleeding, etc., would survive, maybe?  Why do we give others our blood, time, and other precious things?  For no apparent benefit to ourselves?  That does not sound very rational, does it? 

Just now, we were watching the movie “X-Men: The Last Stand” on TV.   Towards the end, Jean Grey’s  uncontrollable alternative personality “Phoenix” began a massacre with her terrible power.  Trying to stop her, Wolverine himself was at the brink of being killed by Phoenix.  At that point, Phoenix asked Wolverine whether he was willing to die for “them” - perhaps referring to the other mutants and humans.  Wolverine told her that he was willing to die for her - meaning Jean Grey, apparently. 

Whether Wolverine was willing to die for other mutants, humans, or Jean Grey, why do we humans think that sacrificing for someone else is such a noble and desirable thing to do?   It is certainly not rational.  Unless there is an implicit assumption of immortality - life after death.  Even then, there must be love involved.  Where does that come from?   Where else but God Himself?