KerryHuish
Hebrews 13:4 Marriage should be honored by all, and the marriage bed kept pure, for God will judge the adulterer and all the sexually immoral.
So yes, there is a clear Bible rule against sex before marriage and extramarital affairs.
A person engaging in sex outside of marriage or inviting other partners into the marriage bed, is not compatible with this principle
Kerry, this verse is clearly referring to a circumstance in which a person is ALREADY married. This says nothing about sex without marriage. Adultery seems to be clearly condemned. But then it is tied to the "sexually immoral". Again, what exactly is sexually immoral? We know God didn't object to concubines. Didn't he in fact even condemn one of David's sons for taking one of his concubines? Solomon also is purported to have had a harem, by his own admission, all the while being blessed with great wisdom.
It can't be denied that there are layers of acceptability here. Which again would explain why the GB may soon loosen up the rules.