"As “feast”, liturgy goes beyond the realm of what can be made and manipulated; it introduces us into the realm of given, living reality, which communicates itself to us. That is why, at all times and in all religions, the fundamental law of liturgy has been the law of organic growth within the universality of the common tradition. Even in the huge transition from the Old to the New Testament, this rule was not breached, the continuity of liturgical development was not interrupted. … Neither the apostles nor their successors “made” a Christian liturgy; it grew organically as a result of the Christian reading of the Jewish inheritance, fashioning its own form as it did so."

-Joseph Cardinal Ratzinger, 

The Feast of Faith: Approaches to a Theology of the Liturgy (1986)