"Sacred scripture begins with the creation of man and woman in the image and likeness of God and concludes with a vision of the "wedding-feast of the Lamb". Scripture speaks throughout of marriage and its "mystery", its institution and the meaning God has given it, its origin and its end, its various realizations throughout the history of salvation, the difficulties arising from sin and its renewal "in the Lord" in the New Covenant of Christ and the Church." (Catechism of the Catholic Church, 1602)
Through the Sacrament of Matrimony, God gives special graces to help married couples with life's difficulties, especially to help them raise their children as loving followers of Christ.
Marriage always involves three parties: the bride, the groom, and God. When two Christians receive the Sacrament of Matrimony, God is with them, witnessing and blessing their marriage covenant. For Catholics, God does this through the priest or deacon who presides at the wedding as the Church's witness.
A consummated sacramental marriage is permanent; only death can break it (Mark 10:1-12, Romans 7:2-3, 1 Corinthians 7:10-11). This holy union is a living symbol of the unbreakable relationship between Christ and his Church (Ephesians 5:21-33).