From Pope St. John Paul II’s Apostolic Exhortation Familiaris Consortio (1981):
The proclamation of the Gospel and its acceptance in faith reach their fullness in the celebration of the sacraments. The Church which is a believing and evangelizing community is also a priestly people invested with the dignity and sharing in the power of Christ the High Priest of the New and Eternal Covenant.137
The Christian family too is part of this priestly people which is the Church. By means of the sacrament of marriage, in which it is rooted and from which it draws its nourishment, the Christian family is continuously vivified by the Lord Jesus and called and engaged by Him in a dialogue with God through the sacraments, through the offering of one’s life, and through prayer.
This is the priestly role which the Christian family can and ought to exercise in intimate communion with the whole Church, through the daily realities of married and family life. In this way the Christian family is called to be sanctified and to sanctify the ecclesial community and the world.
137 Lumen gentium, 10.
— Familiaris Consortio 55