Sure dqhall - that's an eerie verse - but what John is talking about here is not actually about hating life : it's about hating wordly versus spiritual life: i.e. desire vs. devotion . . . when he says "'hating' your life" he's talking about hating worldly things like money, career, assets, popularity, "success" etc, (and therefore loving God instead) - i.e. if you don't "hate" the worldly shallowness of your life, you lose your eternal life.
It's certainly not about hating life itself, of course, because:
For starters, God is life (and says so in the very same book)
For seconders, our job is to rejoice in the Lord always, and that simply can't logically be acheived whilst hating life (in the normal sense of the word)
You don't need to take my word for this - have a look for 'commentaries' and you'll find that scholars have been pretty sure about this interpretation of this particular verse for hundreds of years.