We must not be misled by a habit of referring to prayer as if it were merely linguistic. We respond to God’s address not only in language but with a wide repertoire of gestures and objects. Augustine analyzed ritual action with a formula that became decisive for Western theology: “The word comes to a ritual object, and so there is, … as it were, a visible word.” In this dictum, Augustine directly instanced only “sacrament,” God’s ritual word to us, but his analysis must apply equally to “sacrifice,” our ritual word to God. The life of humanity before God is an antiphony of God’s word to us and our word to God; and the whole antiphony is both audible and “visible.”

—Robert Jenson, Systematic Theology, Volume 2: The Works of God (OUP, 1999), p. 59