2384 Divorce is a grave offense against the natural law. It claims to break the contract, to which the spouses freely consented, to live with each other till death. Divorce does injury to the covenant of salvation, of which sacramental marriage is the sign. Contracting a new union, even if it is recognized by civil law, adds to the gravity of the rupture: the remarried spouse is then in a situation of public and permanent adultery:

If a husband, separated from his wife, approaches another woman, he is an adulterer because he makes that woman commit adultery, and the woman who lives with him is an adulteress, because she has drawn another's husband to herself. (St. Basil, Moralia 73,1:J.P. Migne, ed., Patroligia Greaca (Paris, 1867-1866) 31,849-852)

2385 Divorce is immoral also because it introduces disorder into the family and into society. This disorder brings grave harm to the deserted spouse, to children traumatized by the separation of their parents and often torn between them, and because of its contagious effect which makes it truly a plague on society.

2386 It can happen that one of the spouses is the innocent victim of a divorce decreed by civil law; this spouse therefore has not contravened the moral law. There is a considerable difference between a spouse who has sincerely tried to be faithful to the sacrament of marriage and is unjustly abandoned, and one who through his own grave fault destroys a canonically valid marriage. (cf. Familiaris Consortio 84)

III. Matrimonial Consent

1625 The parties to a marriage covenant are a baptized man and woman, free to contract marriage, who freely express their consent; to be free means:

• not being under constraint;
• not impeded by any natural or ecclesiastical law.

1626 The Church holds the exchange of consent between the spouses to be the indispensable element that makes the marriage.(Code of Canon Law, canon 1057 § 1.) If consent is lacking there is no marriage.

1627 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. (Vatican II, Gaudium et spes 48 § 1; Ordo celebrandi Matrimonium 45; cf. Code of Canon Law, canon 1057 § 2.) This consent that binds the spouses to each other finds its fulfillment in the two becoming one flesh. (Genesis 2:24; cf. Matthew 10:8; Ephesians 5:31)

1628 The consent must be an act of the will of each of the contracting parties, free of coercion or grave external fear. (cf. Code of Canon Law, canon 1103.) No human power can substitute for this consent. (cf. Code of Canon Law, canon 1057 § 1.) If this freedom is lacking the marriage is invalid.

1629 For this reason (or for other reasons that render the marriage null and void) the Church, after an examination of the situation by the competent ecclesiastical tribunal, can declare the nullity of a marriage, i.e., that the marriage never existed. (cf. Code of Canon Law, canons 1095-1107.) In this case the contracting parties are free to marry, provided the natural obligations of a previous union are discharged. (cf. Code of Canon Law, canon 1071.)

1630 The priest (or deacon) who assists at the celebration of a marriage receives the consent of the spouses in the name of the Church and gives the blessing of the Church. The presence of the Church's minister (and also of the witnesses) visibly expresses the fact that marriage is an ecclesial reality.

1631 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: (cf. Council of Trent: DS 1813-1816; Code of Canon Law, canon 1108.)

• 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.

1632 So that the I do of the spouses may be a free and responsible act and so that the marriage covenant may have solid and lasting human and Christian foundations, preparation for marriage is of prime importance.

The example and teaching given by parents and families remain the special form of this preparation.

The role of pastors and of the Christian community as the family of God is indispensable for the transmission of the human and Christian values of marriage and family, (cf. Code of Canon Law, canon 1063.) and much more so in our era when many young people experience broken homes which no longer sufficiently assure this initiation:

It is imperative to give suitable and timely instruction to young people, above all in the heart of their own families, about the dignity of married love, its role and its exercise, so that, having learned the value of chastity, they will be able at a suitable age to engage in honorable courtship and enter upon a marriage of their own. (Vatican II, Gaudium et spes 49 § 3.)