The essential element of the Sacrament of Marriage is the baptized man's and woman's mutual and irrevocable consent to be united as married partners for life in a way which fosters their welfare as individuals and their union as a couple, and is open to giving life to and nurturing children.
To enter such a relationship permanently, one must be free to do so -- psychologically, emotionally, and physically. Mutual consent is at the heart of marriage itself and of marriage as a sacrament. Both individuals must know themselves and each other well enough to make an exclusive commitment that they can keep...in joy and in sorrow, in good times and in bad, until death.
-p. 3 (from "Loving: A Catholic Perspective on Vocational Lifestyle Choices" by Michelle McCarthy)
Matrimony as a sacrament is an act and celebration
of Christian faith. Since the faith of the individuals
being celebrated is the faith of the Church,
a participation in Christ's faith in God, his loving Father,
one must remember that this sacrament is a Church celebration
and not a private event. As such,
it is a celebration for the entire believing community.
- p. 3 (from "Marriage, Ritual and Pastoral Notes",
Canadian Conference of Catholic Bishops)