The use of a lamb as a symbol of Christ is based on such passages as Jn. 1: 29 and Rev. 5: 12. Sometimes a lamb with or near a cross represented the sacrifice of Christ; sometimes a lamb is depicted standing on Mt Zion (cf. Rev. 14: 1). Other passages in the NT suggest the representation of Christian believers as sheep, with the Good Shepherd carrying His lambs or standing among them. After the Trullan Synod in 692 forbade the representation of Christ under the form of a lamb, such imagery was confined to the W. Church. See also Agnus Dei; Paschal Lamb; and prosphora.