This communion is rooted in the natural bonds of flesh and blood, and grows to its specifically human perfection with the establishment and maturing of the still deeper and richer bonds of the spirit: the love that animates the interpersonal relationships of the different members of the family constitutes the interior strength that shapes and animates the family communion and community.
The Christian family is also called to experience a new and original communion which confirms and perfects natural and human communion. In fact the grace of Jesus Christ, "the first-born among many brethren "(56) is by its nature and interior dynamism "a grace of brotherhood," as St. Thomas Aquinas calls it.(57) The Holy Spirit, who is poured forth in the celebration of the sacraments, is the living source and inexhaustible sustenance of the supernatural communion that gathers believers and links them with Christ and with each other in the unity of the Church of God. The Christian family constitutes a specific revelation and realization of ecclesial communion, and for this reason too it can and should be called "the domestic Church."(58)
All members of the family, each according to his or her own gift, have the grace and responsibility of building, day by day, the communion of persons, making the family "a school of deeper humanity"(59): this happens where there is care and love for the little ones, the sick, the aged; where there is mutual service every day; when there is a sharing of goods, of joys and of sorrows.
A fundamental opportunity for building such a communion is constituted by the educational exchange between parents and children,(60) in which each gives and receives. By means of love, respect and obedience towards their parents, children offer their specific and irreplaceable contribution to the construction of an authentically human and Christian family.(61) They will be aided in this if parents exercise their unrenounceable authority as a true and proper "ministry," that is, as a service to the human and Christian well-being of their children, and in particular as a service aimed at helping them acquire a truly responsible freedom, and if parents maintain a living awareness of the "gift" they continually receive from their children.
Family communion can only be preserved and perfected through a great spirit of sacrifice. It requires, in fact, a ready and generous openness of each and all to understanding, to forbearance, to pardon, to reconciliation. There is no family that does not know how selfishness, discord, tension and conflict violently attack and at times mortally wound its own communion: hence there arise the many and varied forms of division in family life. But, at the same time, every family is called by the God of peace to have the joyous and renewing experience of "reconciliation," that is, communion reestablished, unity restored. In particular, participation in the sacrament of Reconciliation and in the banquet of the one Body of Christ offers to the Christian family the grace and the responsibility of overcoming every division and of moving towards the fullness of communion willed by God, responding in this way to the ardent desire of the Lord: "that they may be one."(62)