Definition
Marriage is one of the seven sacraments of the Church, in which God’s blessing is invoked upon a voluntary conjugal union, based on the mutual love of husband and wife, after the image of the spiritual union of Christ and His Church.
Bible Quotes
In marriage a sacrament takes place, performed by God:
“And the LORD God said, ‘It is not good that man should be alone; I will make him a helper comparable to him.’ <...> Then the rib which the LORD God had taken from man He made into a woman, and He brought her to the man. <...> Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh” (Gen. 2:18,22,24)
“The Pharisees came and asked Him, ‘Is it lawful for a man to divorce his wife?’ testing Him. And He answered and said to them, ‘What did Moses command you?’ They said, ‘Moses permitted a man to write a certificate of divorce, and to dismiss her.’ And Jesus answered and said to them, ‘Because of the hardness of your heart he wrote you this precept. But from the beginning of the 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 then they are no longer two, but one flesh. Therefore what God has joined together, let not man separate’” (Mark. 10:2-9)
“Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a harlot? Certainly not! Or do you not know that he who is joined to a harlot is one body with her? For ‘the two,’ He says, ‘shall become one flesh’” (1 Cor. 6:15-16)
“So husbands ought to love their own wives as their own bodies; he who loves his wife loves himself. <...> ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh.’ This is a great mystery, but I speak concerning Christ and the church. Nevertheless let each one of you in particular so love his own wife as himself, and let the wife see that she respects her husband” (Eph. 5:28,31-33) (Greek: τὸ μυστήριον τοῦτο μέγα — “this mystery (sacrament) is great”)
On the Church’s Blessing of Marriage in the 1st Century
Ignatius the God-Bearer, Saint (~37-107)
“But it becomes both men and women who marry, to form their union with the approval of the bishop, that their marriage may be according to God, and not after their own lust”