I Am Impotent
Heard the one about the old man who is listening to an evangelist on the radio, when the evangelist proclaims, "Put one hand on your afflicted part and your other hand on the radio and you shall be healed"? So the old man puts his left hand on his penis and his right hand on the radio, at which point his wife looks over and says: "He said he was going to heal the sick, not raise the dead."