Question: "What does the Bible say about gay marriage / same sex marriage?"
Answer: While the Bible does address homosexuality, it does not explicitly mention gay marriage/same-sex marriage. It is clear, however, that the Bible condemns homosexuality as an immoral and unnatural sin. Leviticus 18:22 identifies homosexual sex as an abomination, a detestable sin. Romans 1:26-27 declares homosexual desires and actions to be shameful, unnatural, lustful, and indecent. First Corinthians 6:9 states that homosexuals are unrighteous and will not inherit the kingdom of God. Since both homosexual desires and actions are condemned in the Bible, it is clear that homosexuals “marrying” is not God’s will, and would be, in fact, sinful.
Whenever the Bible mentions marriage, it is between a male and a female. The first mention of marriage, Genesis 2:24, describes it as a man leaving his parents and being united to his wife. In passages that contain instructions regarding marriage, such as 1 Corinthians 7:2-16 and Ephesians 5:23-33, the Bible clearly identifies marriage as being between a man and a woman. Biblically speaking, marriage is the lifetime union of a man and a woman, primarily for the purpose of building a family and providing a stable environment for that family.
The Bible alone, however, does not have to be used to demonstrate this understanding of marriage. The biblical viewpoint of marriage has been the universal understanding of marriage in every human civilization in world history. History argues against gay marriage. Modern secular psychology recognizes that men and women are psychologically and emotionally designed to complement one another. In regard to the family, psychologists contend that a union between a man and woman in which both spouses serve as good gender role models is the best environment in which to raise well-adjusted children. Psychology argues against gay marriage. In nature/physicality, clearly, men and women were designed to “fit” together sexually. With the “natural” purpose of sexual intercourse being procreation, clearly only a sexual relationship between a man and a woman can fulfill this purpose. Nature argues against gay marriage.