Barnabas’ first theological motivation for the observance of Sunday is eschatological. The eighth day (i.e. Sunday) is to be spent rejoicing because it represents “the beginning of another world” (The Epistle of Barnabas 15, 8). Justin’s first reason for the Christians’ Sunday assembly is the commemoration of the inauguration of creation: “because it is the first day on which God, transforming the darkness and prime matter, created the world” (I Apology 67).