Prior to Jesus, the main purpose of marriage was to produce legitimate, male heirs. The male head of the household wanted to be able to pass his assets down to his own children. Marriages were contracts between families. The government was not involved in marriage in any way. Marriage was not an “institution.” Marriages tended to be utilitarian and many ended in death or divorce.
Divorce was simply the nullification of a contract. It was common and simple. If the wife brought a dowry (her inheritance from her father given to her husband at marriage) into the marriage, she was generally allowed to take it with her when she left. Though if the males in the family agreed on her infidelity, she would forfeit her dowry.
Jesus preached a less utilitarian and more spiritual view of marriage. He made it the “ideal” for a couple to stay married for life. He said several times that a man who divorces his wife and marries another commits adultery. While some believers take this to be a rule against remarriage, those same believers likely do not require adherence to Jesus’ command to the rich young man to sell everything and give it to the poor.
Jesus changed marriage, and the world, not by making rules but by teaching us a new way to live. Rather than keeping divorce easy and common, Jesus encouraged his followers to hang in and work through the problems that come up in marriage. Jesus showed us how to love others in a sacrificial way, rather than sticking to the idea that marriage was for the sole purpose of producing heirs. Jesus’ teachings made marriages last longer and stay stronger.
Some of his early followers in the first few hundred years of church history made other marriage rules:
1. Sex is only for procreation.
2. Even procreation sex shouldn’t be enjoyed, only tolerated.
3. All must remain celibate.
4. Masturbation is forbidden.
5. Homo-erotic sex is forbidden.
Most of these rules have been deemed wrong over time. Some early Christian writers, though, seemed to understand Jesus’ true intention. Tertullian wrote this lovely passage outlining a new view of marriage in “To His Wife”:
Side by side in the Church of God and at the banquet of God, side by side in difficulties, in times of persecution and in times of consolation. Neither hides anything from the other, neither shuns the other, neither is a burden to the other. They freely visit the sick and sustain the needy. They give alms without anxiety, attend the sacrifice without scruple, perform their daily duties unobstructed. 
That shared, holy purpose and friendship between spouses came out of Jesus’ teachings about marriage. The Romans moved things in that direction, making marital monogamy the law, but the Christian agape love changed marriage and changed the world.
Unfortunately, many Christians in the early church, and up to present day, continued to hold on to patriarchy and legalism, despite Jesus spending so much time speaking against legalism and hypocrisy. I think Jesus grieves when his followers make rules for others instead of showing agape love. Let’s look at another act most of us were taught was un-Christian.
 B. Diane Lipsett, “Marriage and Divorce: Early Church,” in The Oxford Encyclopedia of the Bible and Gender Studies ed. Julia M. O’Brien (New York: Oxford University Press, 2014), Volume 1, p. 506.
 Julie Langford, “Marriage and Divorce: Roman World,” in The Oxford Encyclopedia of the Bible and Gender Studies ed. Julia M. O’Brien (New York: Oxford University Press, 2014), Volume 1, p. 495.
 Ibid. 496.
 Mark 10:2-12, Matthew 19:1-9, I Corinthians 7
 Mark 10:17-21
 Tertullian, “To His Wife,” in Miscellanies 2.23.