If you remove the lifetime commitment from marriage and ignore the responsibility of parenthood then marriage can easily just become a temporary business arrangement. When you remove the understanding of the place of sex you muddy the waters on things related to sex such as marriage and children.
The Bible does not have a passage that says, “Marriage shall be defined as the lifetime joining of one man and one woman.” It also does not have a passage that says, “If water gets cold enough, it will turn into ice.” Some things were so plain and simple that nobody ever figured they would need to be stated.
So what is the Biblical morality on this issue?
First, homosexuality is rejected and condemned in the Bible. There is really no question about this. The statements are clear.
(Romans 1:26-27 KJV) For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature: And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.The only way you can get around that is with scissors, smoke and mirrors.
What is God’s ideal in marriage? Three times, in regard to leadership in the church, Paul says they are to be the husband of “one wife” (I Timothy 3:2,12; Titus 1:6). Adultery and fornication are repeatedly denounced.
It is true that there are Biblical examples of multiple wives and concubines. These tend to be the exceptions, not the standard. The cases I am aware of are political leaders, such as Solomon, or patriarchs such as Abraham. There is no approval of the casual or temporary liaisons that are so common today.
Marriage and family are the foundation of society. If we abandon them we abandon civilization and stability. We invite the Wrath of God to be administered to us as individuals and as a country.
homo unius libri