To have a valid marriage both the baptized man and woman must freely express their consent. Neither one of them can be under constraint such as through force or fear. Also, neither one can be impeded by natural or Church law. (1625)*
The Church holds the exchange of consent between the spouses to be the indispensable element that "makes the marriage." If consent is lacking there is no marriage.
The consent consists in a "human act by which the partners mutually give themselves to each other": "I take you to be my wife" - "I take you to be my husband." This consent that binds the spouses to each other finds its fulfillment in the two "becoming one flesh." (1626-27)
Therefore, this consent must be a conscious act of will. Nothing can substitute for this consent.
The priest or deacon is a witness to this consent, and he receives it in the name of the Church. He gives the blessing. The prospective bride and the prospective groom are the ministers of this Sacrament according to the rite of the Roman Catholic Church. Again, this makes the officiating priest or deacon a witness and not the minister of matrimony. The couple give their consent in the presence of the Church's representative and witnesses. This makes their union an ecclesial reality. It is recognized by God and the Church.
This is the reason why the Church normally requires that the faithful contract marriage according to the ecclesiastical form. Several reasons converge to explain this requirement:
- Sacramental marriage is a liturgical act. It is therefore appropriate that it should be celebrated in the public liturgy of the Church;
- Marriage introduces one into an ecclesial order, and creates rights and duties in the Church between the spouses and towards their children;
- Since marriage is a state of life in the Church, certainty about it is necessary (hence the obligation to have witnesses);
- the public character of the consent protects the "I do" once given and helps the spouses remain faithful to it.
The consent by which the spouses mutually give and receive one another is sealed by God himself. From their covenant arises "an institution, confirmed by the divine law, . . . even in the eyes of
society." The covenant between the spouses is integrated into God's covenant with man: "Authentic married love is caught up into divine love." (1631)
Since it is sealed by God Himself, it can never be dissolved. The Church does not have the power to reverse God's will. The grace of matrimony strengthens the conjugal union. Moreover, God helps the husband and wife together to gain holiness and to welcome and educate their children.
*Note: Numbers in brackets refer to the numbers assigned to paragraphs of The Catechism of the Catholic Church.