The arts have always been an essential aspect of the language of the Christian tradition. Visual images, in particular, have provided the most immediate and direct communication of messages about Christian piety and the participation of human beings in Christian worship. The arts transcend the barriers of geography and language and, in a sense, offer an immediate form of instruction. Visual images representing the divine, scriptural and historical characters not only presented a model for the worshipper's attitudes and emotions but also provided an intensity of engagement designed to aid and improve prayer.