Ok so I read this and laughed really hard. I hope you get it.
A pastor went out one Saturday to visit his church members. As he walked to the door of one house, he passed a beautifully kept flower bed. He knocked at the door. It was obvious that someone was home, but nobody came to the door, even though he knocked several times. Finally, the pastor took out his business card, wrote "Revelation 3:20" on the back of it, and stuck it in the door.
The next day, the card turned up in the collection plate. Below the pastor's message was the notation "Genesis 3:10."