From Pope St. John Paul II’s Apostolic Exhortation Familiaris Consortio (1981):
Among the fundamental tasks of the Christian family is its ecclesial task: the family is placed at the service of the building up of the Kingdom of God in history by participating in the life and mission of the Church.
In order to understand better the foundations, the contents and the characteristics of this participation, we must examine the many profound bonds linking the Church and the Christian family and establishing the family as a “Church in miniature” (Ecclesia domestica),114 in such a way that in its own way the family is a living image and historical representation of the mystery of the Church.
It is, above all, the Church as Mother that gives birth to, educates and builds up the Christian family, by putting into effect in its regard the saving mission which she has received from her Lord. By proclaiming the word of God, the Church reveals to the Christian family its true identity, what it is and should be according to the Lord’s plan; by celebrating the sacraments, the Church enriches and strengthens the Christian family with the grace of Christ for its sanctification to the glory of the Father; by the continuous proclamation of the new commandment of love, the Church encourages and guides the Christian family to the service of love, so that it may imitate and relive the same self-giving and sacrificial love that the Lord Jesus has for the entire human race.
In turn, the Christian family is grafted into the mystery of the Church to such a degree as to become a sharer, in its own way, in the saving mission proper to the Church: by virtue of the sacrament, Christian married couples and parents “in their state and way of life have their own special gift among the People of God.”115 For this reason they not only receive the love of Christ and become a saved community, but they are also called upon to communicate Christ’s love to their brethren, thus becoming a saving community. In this way, while the Christian family is a fruit and sign of the supernatural fecundity of the Church, it stands also as a symbol, witness and participant of the Church’s motherhood.116
114 Second Vatican Council Lumen gentium, 11; Apostolicam actuositatem, 11; Pope John Paul II, Homily for the Opening of the Sixth Synod of Bishops (Sept. 26, 1980), 3: Acta Apostolicæ Sedis 72 (1980) 1008.
115 Second Vatican Council Lumen gentium, 11.
116 Cf. ibid., 41.
— Familiaris Consortio 49