The liturgy is an “action of God” that unites us to Jesus Christ through the Holy Spirit (cf. "Sacramentum Caritatis," no. 37).
“The sacraments are efficacious signs of grace, instituted by Christ and entrusted to the Church, by which divine life is dispensed to us. The visible rites by which the sacraments are celebrated signify and make present the graces proper to each sacrament" ( CCC, 1131). “The sacraments are perceptible signs (actions, words) accessible to our human nature" (CCC, 1084).