The Devil can so completely assume the human form, when he wants to deceive us, that we may well lie with what seems to be a woman, of real flesh and blood, and yet all the while 'tis only the Devil in the shape of a woman. 'Tis the same with women, who may think that a man is in bed with them, yet 'tis only the Devil; and...the result of this connection is oftentimes an imp of darkness, half mortal, half devil.
Martin LutherWe ought first to know that there are no good works except those which God has commanded, even as there is no sin except that which God has forbidden.
Martin Luther