confession that there is one Jesus Christ, the only Son of the one Father, who alone has made known (ἐξηγήσατο, “exegeted,” Jn 1:18) the Father. The assertion that there is such a thing as right faith came to be expressed, by the end of the second century, in terms of the canon (rule) of faith or truth, where canon does not mean an ultimately arbitrary list of articles of belief which must be adhered to, or a list of authoritative books which must be accepted, but is rather a crystallization of