"Say AMEN Somebody...." joke

A man is driving down a deserted stretch of highway, when he notices
a sign out of the corner of his eye. It says, "SISTERS OF MERCY HOUSE
OF PROSTITUTION 10 MILES." He thinks it was just a figment of his
imagination and drives on without a second thought. Soon, he sees
another sign which says, "SISTERS OF MERCY HOUSE OF PROSTITUTION 5
MILES," and realizes that these signs are for real. When he drives
past a third sign saying, "SISTERS OF MERCY HOUSE OF PROSTITUTION NEXT
RIGHT," his curiosity gets the best of him and he pulls into the
drive.
On the far side of the parking lot is a somber stone building with a
small sign next to the door reading, "SISTERS OF MERCY." He climbs the
steps and rings the bell. The door is answered by a nun in a long black
habit who asks, "What may we do for you, my son?" He answers, "I saw your
signs along the highway, and was interested in possibly doing business."
"Very well, my son. Please follow me."
He is led through many winding passages and is soon quite disoriented.
The nun stops at a closed door, and tells the man, "Please knock on this
door." He does as he is told and this door is answered by another nun in
a long habit and holding a tin cup. This nun instructs "Please place
$50 in the cup, then go through the large wooden door at the end of this
hallway." He gets $50 out of his wallet and places it in the second
nun's cup. He trots eagerly down the hall and slips through the door,
pulling it shut behind him. As the door locks behind him, he finds
himself back in the parking lot, facing another small sign: GO IN PEACE,
YOU HAVE JUST BEEN SCREWED BY THE SISTERS OF MERCY.