Zwingli’s firm belief in the centrality of the Word of God can be seen in the following which he wrote to the Bishop of Konstanz in 1522:
“To put you in the picture concerning my preaching activity in Zurich: four years ago I preached right through the Gospel according to Matthew. After the Gospel, I continued immediately with the Acts of the Apostles, for now the Church in Zurich ought to see how, and under what authorities, the further proclamation of the Gospel began. There followed at once Paul’s Fist Epistle to Timothy, which seemed to me to be of excellent benefit to the good flock, because it contains, as it were, the rules of the Christian life. In the meantime, certain persons who had a smattering of knowledge had strayed into such ungodly madness that they had almost brought he name of Paul into disrepute, as they gave themselves airs with their seemingly pious and harmless remarks: ‘Who is Paul, anyway? I she not just a man? Certainly he is an Apostle, but only an additional member, not one of the Twelve; for he never spoke with Christ, and he never composed an article of faith; for my part I believe a Thomas or a Scotus just as much as a Paul’. So I expounded the two letters of Peter, the prince of the Apostles, so that they might clearly see whether both the Apostles, filled with the same Spirit, did not say the same thing. When I had finished with that , I took up the letter to the Hebrews, in order that they should learn that Christ is the High Priest; and they have already learned this, to a certain extent”.
(Z I p284f as cited in Locher p27)