A new priest moved into town and went out one Saturday to visit his parishioners. All went well until he came to one house. It was obvious that someone was home, but no one came to the door even after he had knocked several times. Finally, he took out his card, wrote on the back "Revelation 3:20" and stuck it in the door. (Revelation 3:20 reads: "Behold, I stand at the door and knock, if any man hear my voice, and opens the door, I will come in to him, and will dine with him, and he will with me.")
The next day, as he was counting the offering he found his card in the collection plate. Below his message was a notation "Genesis 3:10" ("And he said, I heard thy voice in the garden, and I was afraid, because I was naked.").