CCC 1108 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.1 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.2
1 Cf. Jn 15:1-17; Gal 5:22.
2 Cf. 1 Jn 1:3-7.