A sermon on Ecclesiastes 1:1-11.  I learned a lot about the sin of acedia and ways to respond to it from book God's Country: Faith, Hope, and the Future of the Rural Church by Brad Roth.   I quoted from chapter 2, "Praise in Place: God is Somewhere," several times, specifically on pages 41 and 47.  This sermon leans heavily on that chapter in general and I recommend reading it to learn more.