Something I’ve mentioned here, but this captures it brilliantly.
Ritual is repetition that seeks eternity in the thing repeated, and the Church overflows with the stuff. I genuflect every time I enter a Catholic Church, because no number of genuflections could fully satisfy the desire I have to honor the presence of Christ in the Holy Eucharist. I dip my finger in the holy water and stripe myself with the sign of the cross, because no amount of baptismal water could ever be enough to allow me to fully grasp the ever-depth of what it means to be an adopted son of God. The priest chants his Dominus vobiscum and I my et cum spiritu tuo, and we’ll be chanting it nunc et semper, in saecula saeculorum because no number of repetitions will allow me to comprehend the mystery of Christ truly present in his apostle, the priest. The feasts, the fasts, the holy days of obligations — the Calendar is enshrined repetition, the embrace of an everlasting life, which we cannot conceive of living once and for all, a life we can only live again and again. (This may only mean something to a few, but have it nonetheless: Nietzsche’s demand for an Eternal Return is fulfilled in the Liturgical Calendar.)