A missionary gets sent into deepest darkest Africa and goes to
live with a tribe therein. He spends years with the people,
teaching them to read, write and the good Christian ways. One thing
he particularly stresses is the evils of sexual sin. Thou must not
commit adultery or fornication!
One day the wife of one of the Tribe's noblemen gives birth to a
white child. The village is shocked and the chief is sent by his
people to talk with the missionary. "You have taught us of the
evils of sexual sin, yet here a black woman gives birth to a white
child. You are the only white man that has ever set foot in our
village. It doesn't take a genius to work out what has been going
on!"
The missionary replies: "No, no, my good man. You are mistaken.
What you have here is a natural occurrence - what is called an
albino. Look to thy yonder field. See a field of white sheep, and
yet amongst them is one black one. Nature does this on
occasion."
The chief pauses for a moment then says "Tell you what, you don't
say anything about the sheep, I won't say anything about the white
child"