In the liturgy of the New Covenant every liturgical action, especially the celebration of the Eucharist and the sacraments, is an encounter between Christ and the Church. The liturgical assembly derives its unity from the "communion of the Holy Spirit" who gathers the children of God into the one Body of Christ. This assembly transcends racial, cultural, social - indeed, all human affinities.
Catechism of the Catholic Church 1097
In every liturgical action the Holy Spirit is sent in order to bring us into communion with Christ and so to form his Body. the Holy Spirit is like the sap of the Father's vine which bears fruit on its branches.26 The most intimate cooperation of the Holy Spirit and the Church is achieved in the liturgy. the Spirit who is the Spirit of communion, abides indefectibly in the Church. For this reason the Church is the great sacrament of divine communion which gathers God's scattered children together. Communion with the Holy Trinity and fraternal communion are inseparably the fruit of the Spirit in the liturgy.27
Catechism of the Catholic Church 1108