So we come to 
that verse ...
For God so loved the world
That he gave his only begotten son
That whosoever believeth in him
Should not perish
But have everlasting life.
I wanted to take a closer look at these words "everlasting life." What does it mean? Here's a cool website for translation from the original Greek text of any verse in the New Testament:
http://www.greekbible.com/index.phpYou can click on any word in any verse in the the Greek New Testament and get a paragraph worth of translations!!   
 
Here is what it says for the words "life everlasting" (zoe aionios) in John 3:16
(zoe) 1) life  1a) the state of one who is possessed of vitality or is animate  1b) every living soul  
2) life  2a) of the absolute fulness of life, both essential and ethical, which belongs to God, and through him both to the  hypostatic "logos" and to Christ in whom the "logos" put on human nature  2b) life real and genuine, a life active and vigorous, devoted to God, blessed, in the portion even in this world of those  who put their trust in Christ, but after the resurrection to be consummated by new accessions (among them a more perfect  body), and to last for ever.  
(aionios) without beginning and end, that which always has been and  always will be  2) without beginning  3) without end, never to cease, everlasting