In 1531, the first Protestants clarified some fundamental similarities between the preached word of God and the sacraments, the rites instituted by Christ:
Through the Word and the rite God simultaneously moves the heart to believe and take hold of faith, as Paul says (Rom. 10:17), “Faith comes from what is heard.” As the Word enters through the ears to strike the heart, so the rite itself enters through the eyes to move the heart. The Word and the rite have the same effect, as Augustine said so well when he called the sacrament “the visible Word,” for the rite is received by the eyes and is a sort of picture of the Word, signifying the same thing as the Word. Therefore both have the same effect. (Tappert, 2000a)
The Lord’s Supper was called the visible word, used in contrast to audible word by Augustine in an age of general illiteracy, when words were only written to be read out loud. However, in today’s culture of silent reading, visible word may convey no more than written word, whereas the concept of nonverbal communication, conveying thought by means other than words heard or read, is quite familiar.