Happiness without God?

Some words of wisdom from C.S. Lewis' Mere Christianity,
"God cannot give us a happiness and peace apart from himself, because it is not there.  There is no such thing.  That is the key to history.  Terrific energy is expended - civilizations are built up - excellent institutions devised; but each time something goes wrong.  Some fatal flaw always brings the selfish and cruel people to the top and it all slides back into misery and ruin."
I don't see how anyone can look at the world we live in today, or at any point in human history, and argue with that conclusion.  Where is the panacea of happiness and harmony that mankind has ever come even close to achieving.  What great pinnacle of humanity can we point to that isn't marred by the lust for power?
I know that the lives of celebrities seem to be what everyone should want: fame, wealth, glamour, power.  And yet, never has a year gone by without multiple accounts of drug addiction, alcoholism, and suicide by these whom we are supposed to idolize.  If they haven't found happiness, with everything a consumer culture tells you to want at their fingertips, then nobody can.
This is one of the great tools of evangelism for those who follow Jesus Christ.  We don't have to convince people that their lives are missing something very important without God.  They already know it, they might be trying to fool themselves a little longer with something in God's place, but they know it.  What God's people need to be doing is living lives in obedience, fellowship, charity, and love worth emulating when those who long for what is missing turn their eyes to the Church of Christ.  Our task is not to convince the world that it needs God, our task is to prove through our lives that we've found him.