In chemistry it is common to take two elements and put them into a test tube to observe the reaction. The natural law is that when you put the same two elements together, you always get the same reaction. God gave us a little chemistry here. He said when that which is holy comes into contact with that which is unholy, the holy never makes the unholy better. The holy is always made unclean and defiled by the unholy. It always produces the same reaction. You are not the exception.