In the passage before us we have the remarkable conversion of the man of Gadara. He desires to accompnay Christ but is sent back to tell of what God has done for him. Note: 1. The divine authority for testimonies. Some would dispute the validity of the giving of a testimony as the means of promoting the cause of the Saviour. That is wrong. 2. It is the primary duty of every Christian. This is endorsed by Peter, 1 Peter 3:15. 3. The story of God's mercy is great. 4. His story was one of grace. What great things the Lord did for this undeserving sinner! Tonight I wish, on what is the 42nd anniversary of my conversion, to tell of the Lord's mercy to me.