The third man was Hippolytus, who was a scholarly man more than the other two, and who continued the polemics against/Gnostic movement in exegetic works and church-historical works. His refutation of the heresies is already history, more than the life-and-death struggle as in Irenaeus and Tertullian.
So we have these three men, who saw the situation of the early Church. It’s important for Protestants to see how early most fundamentals of the Roman system were already present in the third century.
The problem of the period, as posited by the Gnostics, was in the realm of authority: the question whether the holy scriptures were decisive, or the secret teachings of the Gnostics. The Gnostic teachers said that Jesus, for instance in the forty days after His resurrection when He was supposed to be together with His disciples, had given them secret insights, and these insights came to the Gnostic theologians and formed the character of Gnostic philosophy and theology. Now against this the Anti-Gnostic Fathers first of all had to establish a doctrine of the Scripture. The Holy Scripture is given by the Logos through the Divine Spirit. Therefore, it’s necessary to fix the canon, and this problem now arose. You see, all these things – and you will find that in my whole lecture – are not created by people who were sitting in their studios and were thinking about the problem, e. g., “Now what about the Bible?: What belongs to it and what doesn’t?” But it was done by people who felt that the very foundations of the Church were threatened by the intrusion of secret traditions which asserted quite different things from what the Biblical writings said. So the decision of the Church as to what shall and what shall not belong to the canon, was a part of the life-and-death struggle with Gnosticism, and can be understood only from there. And this is so with all the statements of the early Church. We have an example in our own time: The restatement of the Lutheran confessions in modern form by the German synods was not a matter of conferences of theologians who were interested in restating the old confessions in a little bit revised form – that was tried, and without any effect or success – but it was done exactly as in the ancient Church: In the moment in which the so-called German Christians – namely the Nazis, who in many respects had similarities to the Gnostic movements – entered the Christian churches; and now the Christian Church had to state formulas of resistance. It was that resistance movement which the Germans could and did put up: namely, resistance of the churches against the intrusion of a pagan, half-gnostic philosophy into Christianity. It is in this way that you must think of the development of Christian dogma. Don’t think of it in terms of professorial studies, as sometimes the theology of the Ecumenical Movement seems to develop… (The danger to the ecumenical movement)is not so much from the Communist side – they are on the outside – as it is if, for instance, a struggle develops between two halves of the Western world, the European and the Anglo- Saxon, where from the one or the other side, the attempt will be made to identify Christianity with, let us say, the American ways of life, as understood by some leaders of the present-day Congress.
Now if this happens, then there would be a real situation of life-and-death struggle: Christianity would have to fight for its very existence. This is what I mean with the serious and realistic character of the theological , development of the early Church, and also with the fixation of the canon.