Is It Wrong to Shack Up if you are a so called Christain? The real question is What does the BIBLE say about fornication? Sexual relationship with someone whom you ARE NOT married to. It is a SIN and it will separate you from God. IT'S THE BIBLE. If you are separated from God you will not make heaven your home when you die or else should Jesus return during your lifetime you will not go in the rapture and will be left to go through the great tribulation. God does not judge us against one another, he judges us based on the Word of God.