Several years ago I wrote A Response to Orson Scott Card when he was trying to defend the notion that marriage was between one man and one woman. I talked of civil contracts and thousands of years of cultural contra-indicators.
Rose is a sweet lady who has lived down the hall for longer than the 15 years I've lived here. She's a conservative Christian who, this year, will be voting for Obama but says she's going to vote Yes on the Minnesota Same Sex Marriage Amendment, defining marriage only as between one man and one woman. We have been trading Biblical citations in support of our positions. She's fond of saying, "Hate the sin, love the sinner." That's all well and good if there were sin involved, and if this were a religious discussion, but this is a civil matter and the Bible comes pretty hard on the "love" part. Here is my list, fairly quickly cobbled together for her but somewhat expanded and with links for the web.
Quotes are from Biblos, King James Bible translation because I thought it would be more convincing to Rose.
Jesus says nothing of hating gays, but talks much of love:
John 13:34, 35 "A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. By this shall all men know that ye are my disciples, if ye have love one to another."
Romans 13:8-10 reads as follows (quoting Paul): "Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law. For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself. Love worketh no ill to his neighbour: therefore love is the fulfilling of the law."
Jesus was big on forgiveness and turning the other cheek. While I think there are limits to loving thine enemies, it's clear that you can only call yourself a follower of Jesus if love your neighbors who are following the Commandments, with love being the prime commandment.
Some Bible (ie Old Testament) commentary on marriage:
Genesis 4:19 "And Lamech took unto him two wives: the name of the one was Adah, and the name of the other Zillah."
Genesis 16:3 "And Sarai Abram's wife took Hagar her maid the Egyptian, after Abram had dwelt ten years in the land of Canaan, and gave her to her husband Abram to be his wife." See also Genesis 21:1-13, Genesis 25:1 and Genesis 25:6 "But unto the sons of the concubines, which Abraham had, Abraham gave gifts, and sent them away from Isaac his son, while he yet lived, eastward, unto the east country."
Exodus 21:10, "If he take him another wife; her food, her raiment, and her duty of marriage, shall he not diminish."
Deuteronomy 21:15-17 "If a man have two wives, one beloved, and another hated, and they have born him children, both the beloved and the hated; and if the firstborn son be hers that was hated: Then it shall be, when he maketh his sons to inherit that which he hath, that he may not make the son of the beloved firstborn before the son of the hated, which is indeed the firstborn: But he shall acknowledge the son of the hated for the firstborn, by giving him a double portion of all that he hath: for he is the beginning of his strength; the right of the firstborn is his." [Which seems to me not only to prove that the Bible allowed polygamy, but speaks to raising children and therefore adoptive children.]
2 Samuel 5:13 "And David took him more concubines and wives out of Jerusalem, after he was come from Hebron: and there were yet sons and daughters born to David."
1 Kings 11:3 "And he [Solomon] had seven hundred wives, princesses, and three hundred concubines: and his wives turned away his heart."
2 Chronicles 11:21 "And Rehoboam loved Maachah the daughter of Absalom above all his wives and his concubines: (for he took eighteen wives, and threescore concubines; and begat twenty and eight sons, and threescore daughters.)"
Rose and others who cite the Bible like to quote Leviticus, which does indeed have a lot to say about marriage. Most often cited:
Lev. 18:22 "You shall not lie with a man, as with a woman: it is abomination."
Amongst other abominations in Leviticus:
Lev. 11:7 "And the swine, though it divides the hoof, and is cloven footed, yet it chews not the cud; it is unclean to you."
Lev. 11:10 "And all that have not fins and scales in the seas, and in the rivers, of all that move in the waters, and of any living thing which is in the waters, they shall be an abomination unto you" [In other words, not keeping kosher is as much an abomination as homosexuality]
A couple of more from Leviticus: Lev 20:9 "For every one that curses his father or his mother shall be surely put to death: he has cursed his father or his mother; his blood shall be upon him." Lev 24:16 "Whoever blasphemes the name of the LORD shall surely be put to death. All the congregation shall stone him. The sojourner as well as the native, when he blasphemes the Name, shall be put to death." [Was Pat Robertson stoned to death?]
Okay, back to the New Testament on marriage:
Matt 25:1–13, Jesus' Parable of the Ten Virgins "Then shall the kingdom of heaven be likened unto ten virgins, which took their lamps, and went forth to meet the bridegroom.... the bridegroom came, and those who were ready went in with him to the wedding feast; and the door was shut."
Meanwhile, Matt 19:9 "And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery." [In other words, if you divorce and remarry, you have committed adultery.]
The Bible is kinder to women than the New Testament, though that's relative.
1 Corinthians 14:34 "Let your women keep silence in the churches: for it is not permitted unto them to speak; but they are commanded to be under obedience, as also saith the law." Conclusion: The Bible and the New Testament say a lot about marriage and sexual relationships, but drawing any single conclusion is specious. The moral relativists want strict adherence to one passage but completely ignore others. Their Biblical logic is flawed. Marriage is a civil matter as much as a spiritual bonding, and if you're not going to support love then you must support the contract.
Personal observation: We are created in G_d's image. It's a grave mistake to create G_d in our image. There's much that we don't know. What we do know is that virtually all religious figures, notably Jesus, want us to be nice to each other.