Tertullian followed Irenaeus in every particular. He also interpreted the (Romish) baptismal confession, represented it, thus explained, as the _regula fidei_,[41] and transferred to the latter the attributes of the confession, viz., its apostolic origin (or origin from Christ), as well as its fixedness and completeness.[42] Like Irenaeus, though still more stringently, he also endeavoured to prove that the formula had descended from Christ, that is, from the Apostles, and was incorrupt. He based his demonstration on the alleged incontestable facts that it contained the faith of those Churches founded by the Apostles, that in these communities a corruption of doctrine was inconceivable, because in them, as could be proved, the Apostles had always had successors, and that the other Churches were in communion with them (see under C). In a more definite way than Irenaeus, Tertullian conceives the rule of faith as a rule for the faith,[43] as the law given to faith,[44] also as a "regula doctrinae" or "doctrina regulae" (here the creed itself is quite plainly the regula), and even simply as "doctrina" or "institutio."[45] As to the content of the _regula_, it was set forth by Tertullian in three passages.[46] It is essentially the same as in Irenaeus. But Tertullian already gives prominence within the _regula_ to the creation of the universe out of nothing,[47] the creative instrumentality of the Logos,[48] his origin before all creatures,[49] a definite theory of the Incarnation,[50] the preaching by Christ of a _nova lex_ and a _nova promissio regni coelorum_,[51] and finally also the Trinitarian economy of God.[52] Materially, therefore, the advance beyond Irenaeus is already very significant. Tertullian's _regula_ is in point of fact a _doctrina_. In attempting to bind the communities to this he represents them as schools.[53] The apostolic "lex et doctrina" is to be regarded as inviolable by every Christian. Assent to it decides the Christian character of the individual. Thus the Christian _disposition and life_ come to be a matter which is separate from this and subject to particular conditions. In this way the essence of religion was split up--the most fatal turning-point in the history of Christianity.