<< 1st it refers to apostolic doctrine given by divine inspiration (2 Thess. 2:15; 3:6). The churches are bound to obey this tradition as it is supernaturally recorded in the New Testament Scripture. >>
First sentence is true. Second sentence also true, but 2 Thess 2:15 does not refer to “New Testament Scripture” (meaning a 66-book biblical canon), it refers to both oral and written supernaturally inspired apostolic teaching. Another problem again is the meaning and interpretation of this tradition, that’s where the authority of the Church enters.
<< Therefore, though it is true that “the Bible itself is a sort of tradition” this does not mean that it is merely another of various authoritative traditions. The Bible alone is GOD INSPIRED tradition. >>
Ask them to give you the biblical verse that teaches “the Bible alone is God inspired tradition.” There is no verse that teaches that, and quite a few that contradict it: 1 Thess 2:13; 2 Thess 2:15; 1 Cor 2:4,7,13 off the top.
There is no biblical verse that teaches (A) what the “Bible alone” is, and (B) that the “Bible alone” is God inspired tradition. If the person wants to say all God inspired oral teaching of the apostles was lost or corrupted by the early Church, that’s another issue. But there is no verse that teaches the “Bible alone” is God inspired tradition. You have them nailed right there.
Then you might go into a little elaboration of what the early Fathers meant by tradition, and here is a little help from Yves Congar:
(A) The true Catholic Faith and true interpretation of the Scriptures is found only in the Church which is bound up with the succession of its ministers (apostolic succession, not of doctrine only, but of its bishops, ministers, pastors succeeding the authority of the apostles);
(B) The “rule of faith” or “rule of truth” was not the whole of Tradition; it may be the principal part, but there are other things transmitted from the apostles by tradition: rules of conduct/practice, behavior, on worship/liturgy, etc.
© The content of tradition consisted “materially” of the Scriptures, but “formally” of the Faith of the Catholic Church, its reading of the Scriptures in the Creed, etc; the mere text of Scripture alone was insufficient; heretics also quoted Scripture but they did not read that Scripture in the context of the Tradition or the orthodox Faith of the Catholic Church;
(D) The Catholic Church alone has received the apostolic deposit of truth, for in her the Holy Spirit of truth lives (John 14:16f; 16:13f); the Church alone is the sole inheritor of the true Christian teaching from God through Christ to the Apostles;
(E) This Tradition – the Church’s Tradition – is itself oral; and if there were no NT Scriptures it would have been sufficient for the Church to follow “the order of tradition” received from the apostles; in the minds of the early Christians it made no difference if the transmission was purely oral since there was an assured connection to the apostles through the Churches founded by the apostles to guarantee authenticity;
(F) Scripture was everything for the Fathers, and Tradition was everything also;
(G) What was the nature of the Church of the Fathers? It was one universal visible Church ruled by a hierarchy of bishops, presbyters/priests, deacons, etc in succession from the apostles (apostolic succession, again not “succession of doctrine” only);
(H) The entire activity of the Fathers demonstrates that they united three terms that were separated and set in opposition by the controversies of the 16th century – these three terms were Scripture, Tradition, and Church; it was always affirmed that Scripture is the rule and norm of faith only when conjoined to the Church and her Tradition;
(I) Hence, the Scriptures were never considered by the Fathers as formally “sufficient” or exclusive.