Yin Yang is related all the time. For example, Good and Evil or Female and Male. The good cannot exist without evil. Same to Jesus and Satan. The picture on left hand side is Jesus and the right hand side is Satan. Actually they are same picture and either flip one of the pictures, you will see the same thing. It depends on how you see this illusion image.
Note: The author is a spanish artist and his name is Harpo.
Credit: julio (Thanks for telling me the original source and the author name)