An appreciation of the Catholic understanding of the sacrament of marriage: God who is love and who created man and woman for love has called them to love. By creating man and woman he called them to an intimate communion of life and of love in marriage: “So that they are no longer two, but one flesh”
(Matthew 19:6).

God said to them in blessing “Be fruitful and multiply”
(Genesis 1:28).

The marital union of man and woman is by its very nature ordered to the communion and good of the couple and to the generation and education of children. According to the original divine plan this conjugal union is indissoluble, as Jesus Christ affirmed: “What God has joined together, let no man put asunder”
(Mark 10:9).

Christ not only restored the original order of matrimony but raised it to the dignity of a sacrament, giving spouses a special grace to live out their marriage as a symbol of Christ’s love for his bride the Church: “Husbands, love your wives as Christ loves the Church”
(Ephesians 5:25).

Source: Catechism of the Catholic Church