From Steve Camp's blog:
I was on a famous Christian TV show several years ago before their demise. During a 'commercial' break, the host of the program told me if I would give $100 to his ministry the Lord would give me back $1,000... I asked him politely, "Sir, where does it say foolish written on me?" He was a bit shocked and asked me, "don't you believe that the Lord will bless you by giving your money to our ministry?" I told him, "No I don't." And that furthermore he didn't even believe such a thing. He was again a bit surprised by my response and said, "Yes I do." I answered, "No, you don't." He said, "YES, I do." I said, "NO... you don't." With a puzzled look on his face he frustratingly said, "Why do you keep telling me that I don't believe this?" I said, "Simple. If you really believe this, then why don't you give your $100 to God, He'll give you a $1,000 back, and you'll quite asking me for mine?" He looked at me with that dumbfounded kind of quasi pseudo-theological televangelist deer in the headlights don't bother me with doctrine look, and replied, "I never thought of that before." I quietly muttered, "I think that's the problem."