The communion between God and His people finds its definitive fulfillment in Jesus Christ, the Bridegroom who loves and gives Himself as the Savior of humanity, uniting it to Himself as His body.

He reveals the original truth of marriage, the truth of the “beginning,”[27] and, freeing man from his hardness of heart, He makes man capable of realizing this truth in its entirety.

This revelation reaches its definitive fullness in the gift of love which the Word of God makes to humanity in assuming a human nature, and in the sacrifice which Jesus Christ makes of Himself on the Cross for His bride, the Church. In this sacrifice there is entirely revealed that plan which God has imprinted on the humanity of man and woman since their creation[28]; the marriage of baptized persons thus becomes a real symbol of that new and eternal covenant sanctioned in the blood of Christ. The Spirit which the Lord pours forth gives a new heart, and renders man and woman capable of loving one another as Christ has loved us. Conjugal love reaches that fullness to which it is interiorly ordained, conjugal charity, which is the proper and specific way in which the spouses participate in and are called to live the very charity of Christ who gave Himself on the Cross.

In a deservedly famous page, Tertullian has well expressed the greatness of this conjugal life in Christ and its beauty: “How can I ever express the happiness of the marriage that is joined together by the Church strengthened by an offering, sealed by a blessing, announced by angels and ratified by the Father? …How wonderful the bond between two believers with a single hope, a single desire, a single observance, a single service! They are both brethren and both fellow-servants; there is no separation between them in spirit or flesh; in fact they are truly two in one flesh and where the flesh is one, one is the spirit.”[29]