So then, brothers, stand firm and hold to the traditions that you were taught by us, either by our spoken word or by our letter.
Yep, that's about the only verse that ever gets cited and for good reason. But it doesn't refer to Sacred Tradition AKA Holy Tradition! It's merely the similarity of the words that is being relied upon, and it's only a similarity. They aren't spelled the same, if you notice.
Tradition vs traditions.
The Biblical reference is to traditions. Which traditions are not specified there and we do not know what actions, etc. the statement might have been referring to. Yet the Church says that it can just decide for itself.
The "traditions" referred to in that verse already were in evidence to the listeners or else the instruction would have been meaningless and confusing. They probably refer to attending synagogue, continuing to observe the usual moral admonitions, and so on. But actually there is nothing specific there and there is no reference to it determining doctrine!
But with "Holy Tradition" the idea is that new
doctrines are being made through later time as the popular imagination defines them. And these are supposed to be continuous through church history and throughout the length and breadth of the church. In practice, that's not adhered to.
So, in short, that verse you cited does not refer to the Catholic substitute for Sola Scriptura.
Secondly, the word of God is not limited to Sacred Scripture.
That's just speculation or a theory without any substance.
Thirdly - you rely on "something else" yourself. For example, you hold that the book of James is the inspired word of God, but that teaching is not found within the text of the Bible itself. You obtained that teaching via the tradition of the Church.
Do we not both agree that James
is in the Bible, then? Yes, we do. If that is so, then I'm not relying upon anything other than the Bible!
Fourth, nobody wrote that there is something else that "beats" the word of God.
If you are to say--as the opponents of Sola Scriptura necessarily DO say-- that the Bible is
not supremely authoritative, and then the church proposes an alternative (Tradition) to the Bible, that's what is being said...that the word of God is not above everything else.
But how can it seriously be denied that God IS, in fact, supreme?
Fifth, Catholics do not argue that " legends, folk tales, customs, the opinions of theologians . . . " are equal to the word of God.
That's what "Sacred Tradition" consists of. I am not sure that you are aware of this fact.