I preached this sermon on June 28, 2009, at Bethel Evangelical Free Church in Fairmont, MN. I preach from Ecclesiastes 2 and John 4, pairing them together given that they touch on the same basic idea, but from entirely different angles.
The basic structure of the first half of the sermon (pairing Eccl. and John together) was taken from a similar sermon preached by Matt Chandler of the Village Church. On top of this I did a lot of research, relying heavily on the works of John Calvin, Gary Burge, C.S. Lewis, Walt Kaiser, and of course, Matt Chandler. The final text of the sermon is entirely of my own pen (or rather, computer keyboard), although I borrowed a phrase or two from Chandler, specifically in the summary of the Gospel at the very end.
The sermon was delivered on little sleep, being powered entirely by the Holy Spirit and copious amounts of caffeine.