from Morality: Memory and Desire, by Luigi Giussani:
The Christian life depends upon the eucharistic sacrament as a spring or a source out of which can be drawn a motivation that is sufficient for real moral commitment (cf. 1 Corinthians 10:14-22). It is from within the context of such an offering that a correct Christian attitude on morality is formed (cf 1 Corinthians 11:17-26).
However, the great sign that is the Eucharist is caught up and enlarged in an even greater sign, the Church, the only truly adequate sign of the Presence of "the fullness of him who fills all in all" (Ephesians 1:23).
This "body, joined and knit together by every joint with which it is supplied, when each part is working properly, grows and upbuilds itself in love" (Ephesians 4:16). This Body is the place where morality arises and is nourished and grows in love.
To awaken the moral conscience of somebody is a reality that belongs totally to the unity in which all Christians live as brothers through baptism (cf Galatians 3:26-27 : "For in Christ Jesus you are all sons of God through faith. For as many of you as were baptized into Christ have put on Christ"). This unity is preserved and developed by authority (cf. Ephesians 2:20 : "built upon the foundation of the apostles and prophets") and its purpose is to stimulate a kind of self-expression that is exercised for the good of the whole community. All this is the true basis for a real pedagogy in Christian morality.
The immanence of the mystery of community, to the extent that it is recognized, loved, and participated in, penetrates our being as if by osmosis with new moral standards and new moral sensitivity (pp 172-173)
