CCC 1141 The celebrating assembly is the community of the baptized who, “by regeneration and the anointing of the Holy Spirit, are consecrated to be a spiritual house and a holy priesthood, that through all the works of Christian men they may offer spiritual sacrifices.”¹ This “common priesthood” is that of Christ the sole priest, in which all his members participate:²
Mother Church earnestly desires that all the faithful should be led to that full, conscious, and active participation in liturgical celebrations which is demanded by the very nature of the liturgy, and to which the Christian people, “a chosen race, a royal priesthood, a holy nation, a redeemed people,” have a right and an obligation by reason of their Baptism.³

1 LG 10; cf. 1 Pet 2:4-5.
2 Cf. LG 10; 34; PO 2.
3 SC 14; Cf. 1 Pet 2:9; 2:4-5.