The institution of marriage is under attack like never before. What was once commonly referred to as sin has put on a new face. After living together for a few years and having a number of children out of wedlock a couple might remark, "Well, it's like we are married". If things go sour however and the relationship flies apart they can easily walk away from any responsibility because "we were never officially married" on paper. A one night stand might be considered a sin making the woman a whore, the man a whoremonger, but if they live together for a time then it becomes socially acceptable. Its a bit like considering a thief who robs a bank once a criminal, but if he continues the practice every week then it becomes a normal tradition and the alarms quit sounding. It's just the cost of doing business. Besides everyone is doing it so why not, eh? As the farmer would say, "If you can get the milk for free, why buy the cow?"
The traditional Jewish contract of marriage, or Ketuba, had been officially codified as civil law by Simeon ben Shetach about 80 B.C. It spelled out legal obligations in case of death or divorce. A divorce was called a "Get" from an Akkadian word meaning a "court writ". Both the Ketuba and Get were hand written contracts based on centuries of Jewish Scripture, history and tradition (Deu 24:1).
Lack of trust or fear of commitment is often the root of why people are not willing to enter into a legal contract of marriage. "Once burned, twice shy" they say. People who have watched the marriage of parents or friends fail, or have had a relationship crash and burn themselves, are less likely to commit to traditional marriage. They can dream up all kinds of excuses to get around it. In some cases a woman will shun marriage because she likes the thrill of dating and the leverage of being able to walk out at any time as a means to blackmail the partner. He will treat me better if he thinks I might leave, the woman might think. So the man therefore finds himself a slave to a whore. Sooner or later the package will lose its shine however and the true inner person will be revealed. "Or do you know that the one who joins himself to a harlot is one body with her? For He says, 'The two shall will become one flesh'" (1 Cor. 6:16).
Based on Jewish tradition Apostle Paul dedicated a whole chapter in his first epistle to the Corinthians (chapter seven) on the marriage relationship and obligation. The basic guidelines were because of immoralities he says.
At one time we could point to the Scripture where we are instructed to obey the laws of the land (Rom. 13, Titus 3:1) but now that same sex marriage has become part of the norm in our society we have to re-examine the foundation of our principles. Typical of the cults who redefine words and religious terms the LGBTQ movement has attacked our cultural standards to fit their lifestyle, therefore we must hold our ground against the tide of deception. See 1 Peter 3:1-7 for more reference to the biblical model.
With pressure from fundamentalist Mormons and Muslims we are being challenged with the idea of polygamy. They will quickly point to many biblical characters that had more than one wife. However, the Old Testament or TENACH should always be interpreted in the light of the New Testament. Based on the failure of those in the past such as Solomon who took many wives Paul gave some basic guidelines for the pillars of Christian society, they must be "above reproach ..the husband of wife..." (1 Tim. 3:2, Titus1:7)