A minister was preaching a sermon on "living water." At one point he said, "God's living water is like the water flowing in the Mississippi River. It's free." After the sermon a skeptic came up to him and observed, "If the water in the Mississippi river is free, why do you pass the plate to take up a collection during the church service." Unfazed the pastor replied, "Well, while the water is free, you do have to pay to get it piped directly to your door."
(Topper Council, Southland Baptist Temple, Paducah, KY; via Sermon Fodder and Joke A Day Ministries)