LEX CREDENDI

LEX CREDENDI. Literally, this Latin phrase means the “law of what must be believed.” It is the equivalent of the earlier 2nd c. expressions, kanon tes aletheias (rule of truth) and regula fidei (rule of faith), advanced by Irenaeus and Tertullian (qq.v.), respectively, and it means the content of the faith that the Church professes and demands of its members. From the 2nd c. onward, this amounted to the faith confessed by the Christian at Baptism (q.v.). Later, longer formularies were composed by Church councils. Such included the Nicene-Constantinopolitan Creed, still recited by the candidate just prior to Baptism, and the definitions of the Ecumenical Councils (qq.v.).