The Pharisees approached Jesus and asked, “Is it lawful for a husband to divorce his wife?” They were testing him. He said to them in reply, “What did Moses command you?” They replied, “Moses permitted him to write a bill of divorce and dismiss her.” But Jesus told them, “Because of the hardness of your hearts he wrote you this commandment. But from the beginning of creation, ‘God made them male and female. For this reason a man shall leave his father and mother [and be joined to his wife], and the two shall become one flesh.’ So they are no longer two but one flesh. Therefore what God has joined together, no human being must separate.” In the house the disciples again questioned him about this. He said to them, “Whoever divorces his wife and marries another commits adultery against her; and if she divorces her husband and marries another, she commits adultery.” (Mark 10:2-12)
A parallel Gospel passage can be found in Matthew: Some Pharisees approached him, and tested him, saying, “Is it lawful for a man to divorce his wife for any cause whatever?” He said in reply, “Have you not read that from the beginning the Creator ‘made them male and female’ and said, ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’? So they are no longer two, but one flesh. Therefore, what God has joined together, no human being must separate.” They said to him, “Then why did Moses command that the man give the woman a bill of divorce and dismiss [her]?” He said to them, “Because of the hardness of your hearts Moses allowed you to divorce your wives, but from the beginning it was not so. I say to you, whoever divorces his wife (unless the marriage is unlawful) and marries another commits adultery.” (Matthew 19:3-9)
At the Sermon on the Mount, Jesus also taught about divorce: “It was also said, ‘Whoever divorces his wife must give her a bill of divorce.’ But I say to you, whoever divorces his wife (unless the marriage is unlawful) causes her to commit adultery, and whoever marries a divorced woman commits adultery. (Matthew 5:31-32)
In the dialogue between Jesus and the Pharisees on the subject of divorce, Jesus declared that the law of Moses permitted divorce (Deuteronomy 24:1) only because of the hardness of their hearts (Mark 10:4–5; Matthew 19:8). In citing Genesis 1:27 and 2:24, Jesus proclaimed that concerning human marriage, permanence has been the divine intent from the beginning (Mark 10:6–8; Matthew 19:4-6a). He reaffirmed this with the declaration that what God has joined together, no human being must separate (Mark 10:9; Matthew 19:6b).
Jesus’ teaching on marriage is so important, that Jesus said to the disciples: “Amen, I say to you, whoever does not accept the kingdom of God like a child will not enter it.” (Mark 10:15) In other words, whoever does not put total dependence upon and obedience to the Gospel will not enter the kingdom of God. (cf. Mt 18:3–4)
There is an intimate connection between marriage and life: marriage is the fundamental institution for life. The love between husband and wife is meant for welcoming, forming, and educating new life. The inseparability of the unitive and procreative aspects of the marital act is expressed in the love between spouses, the responsibilities of mothers and fathers, and the rights of children.
The Church will never waver in her teaching that marriage is the union of a woman and a man. Marriage is the union of two distinct persons: man and woman, who, in the Sacrament of Matrimony, signify the union between Christ and his Church. From the beginning, man and woman are made for each other.
The Church’s teachings on marriage and sex are deeply connected: Human sexuality is ordered to the conjugal love of man and woman, and the physical intimacy of the spouses is a sign and a pledge of spiritual communion. (CCC 2360) Many people in the world view sex as a recreational activity; that it may be deliberately made sterile and that sex has no moral or social significance. This downgrading of the sexual act to mere pleasure, rather than the true and complete union of man and woman, has increased the isolation between them, because sex becomes focused on self-pleasure, rather than on mutual self-giving. Instead of two persons giving to each other, they take from one another.
The love between husband and wife is ordered to a lifetime of communion with God and each other, such that it is open to creating a new human being which they will love and care for together. Even as God gives to husbands and wives a share in His creative power, there will be some spouses who cannot bear children. But such couples are no less loved by God, and they can still have a married life that is filled with love and meaning. Their love for each other becomes complete and fruitful when it is open to the needs of the poor, to the needs of orphans, and to the needs of the world.
On the other hand, when married couples deliberately suppress the creation of new life by using contraception, they deny the inherent meaning of married sexuality and it harms their unity. With the use of contraception, a spouse treats the other more like an object rather than a person. The widespread use of contraception in society has resulted in an increase of premarital sex, cohabitation, adultery, divorce and abortion. When contraception fails, many couples resort to abortion. Not respecting married love’s power to create new life has eroded the respect for life and the sanctity of marriage.