Well, this thread has lost its steam, and I’ve lost interest in continuing the debate. I’ve been reading a bunch of books I ordered by Craig Blomberg, Gary Habermas, Mike Licona, William Lane Craig and J. Warner Wallace. If you want to read just one, go with Cold Case Christianity by Wallace as a good starting point.
In conclusion, I want to say that Catholics do NOT need the Spiral Argument. In my opinion, it is a tool that we can use to help our non-Catholic brothers and sisters to understand why we can be confident that the Bible is inspired. But, of course, Catholics place their confidence in the Church built by Jesus. Fr. Adrian Fortescue made the argument this way over a century ago:
"The [Catholic] position is this: there are two kinds of proofs for any dogma. The main proof, the most efficient in any way, the proof that is the real motive for every Catholic, is simply that this dogma is taught now by the Church of Christ, that Christ has given to his Church his own authority, so that we can trust the Church as we trust Christ himself. “Who heareth you, heareth me” (Luke 10:16). The argument is the same for every dogma (that is why the Catholic position is essentially simple, in spite of apparent complexity); it can be understood by the most ignorant, as the religion of Christ must be (it is impossible for every child and peasant to make up his own Christianity for himself by his interpretation of Scripture or the Fathers…). This position admits no vagaries of private judgment for each dogma. No variety of interpretation is possible as to what the Catholic Church of today teaches, or, if such misunderstanding should occur, the Church is there to declare her mind. Even the most fundamental dogmas rest ultimately on the teaching of the Catholic Church today, even, for instance, that of the Holy Trinity. All we suppose, before we come to the Church, is that our Lord Jesus Christ was a man sent by God and whom we must follow if we wish to serve God in the proper way; that he founded one visible Church, to which his followers should belong; that this Church is, as a matter of historic fact, the communion of Rome (not, however, supposing anything about the papacy, but supposing only visible unity and historic continuity). This much must be presupposed and therefore does not rest on the authority of the Church. All else does.
“But there is another kind of argument for each dogma, taking each separately and proving that this was taught by Christ and has been believed from the beginning. This line of argument is neither so convincing nor so safe. It does now involve our private judgment as to whether the ancient texts do, or do not, really prove what we claim. It requires knowledge of the texts, of dead languages; to be efficient it requires considerable scholarship. It is impossible that our Lord should give us a religion requiring all this before you know what it is. This direct proof of each dogma can be only confirmation of the general argument for all, taken from the present teaching of the Church. But it is a most valuable confirmation, which we are always ready to offer, as long as it is understood that it is not the main reason of our belief. I am quite sure that Matthew 16:18 and the Church Fathers Clement of Rome, Irenaeus, Chrysostom and Augustine all say what I believe about the Bishop of Rome. But I do not base my faith on what they say; I do not really care a jot whether convenire ad means “agree with” or “to go”. I base my faith on what the Catholic Church of today says. That alone is quite enough for all of us; in this we have an argument perfectly clear, convincing, final, the same for the student of patrology as for a peasant who can neither read nor write” (Adrian Fortescue, The Early Papacy to the Synod of Chalcedon in 451, [San Francisco, Ignatius Press, 2008], 26-27).
