My friend, Matt Perman, recently guest blogged at the Leadership Summit at Willow Creek. He wrote that John Dickson's message on humility was the best he's heard on the subject. Dickson is Director of the Centre for Public Christianity and Sr. Minister, St. Andrews Anglican Church, Sydney, Australia. I had the privilege of meeting him at a conference we held for pastors back in 2008. He's the real deal - probably the clearest (and most encouraging) speaker on the topic of evangelism I've ever heard. I encourage you to read John's books and listen to some of his messages here.