A eucharistic form of Christian life, membership in the Church
76. The importance of Sunday as the Dies Ecclesiae brings us back to the intrinsic relationship between Jesus' victory over evil and death, and our membership in his ecclesial body. On the Lord's Day, each Christian rediscovers the communal dimension of his life as one who has been redeemed. Taking part in the liturgy and receiving the Body and Blood of Christ intensifies and deepens our belonging to the one who died for us (cf. 1 Cor 6:19ff; 7:23). Truly, whoever eats of Christ lives for him. The eucharistic mystery helps us to understand the profound meaning of the communio sanctorum.
Communion always and inseparably has both a vertical and a horizontal sense: it is communion with God and communion with our brothers and sisters. Both dimensions mysteriously converge in the gift of the Eucharist. "Wherever communion with God, which is communion with the Father, with the Son and with the Holy Spirit, is destroyed, the root and source of our communion with one another is destroyed. And wherever we do not live communion among ourselves, communion with the Triune God is not alive and true either."(215) Called to be members of Christ and thus members of one another (cf. 1 Cor 12:27), we are a reality grounded ontologically in Baptism and nourished by the Eucharist, a reality that demands visible expression in the life of our communities.
The eucharistic form of Christian life is clearly an ecclesial and communitarian form. Through the Diocese and the parish, the fundamental structures of the Church in a particular territory, each individual believer can experience concretely what it means to be a member of Christ's Body. Associations, ecclesial movements and new communities – with their lively charisms bestowed by the Holy Spirit for the needs of our time – together with Institutes of Consecrated Life, have a particular responsibility for helping to make the faithful conscious that they belong to the Lord (cf. Rom 14:8). Secularization, with its inherent emphasis on individualism, has its most negative effects on individuals who are isolated and lack a sense of belonging. Christianity, from its very beginning, has meant fellowship, a network of relationships constantly strengthened by hearing God's word and sharing in the Eucharist, and enlivened by the Holy Spirit.