"So, you’re arguing that the Old Testament is a more authoritative rule than the Word of God which the Bereans received from the Church."
"1st. The Apostles were Teaching. That is the Tradition we call “Magisterium.”
"2nd. I repeat, the Apostles were Teaching. That means they were passing down the Traditions of Christ by Word. That is simply called, “Sacred Tradition.”
"3rd. The Bereans looked up the Sacred Tradition, the word of the Apostles, in Scripture."
There is nothing present in the context of Acts 17 mentioning the concept of Roman Catholic "sacred tradition", nor the office of Magisterium.
The "traditions" that were being delivered in the first century were primarily the simple gospel teachings of Jesus Christ. The faith was "once for all" delivered to the saints (Jude 3). There were no mysterious, nebulous, extra-biblical body of traditions being preached to these Hellenistic Jews. Consider the following passages of Scripture:
"Now when they had passed through Amphipolis and Apollonia, they came to Thessalonica, where was a synagogue of the Jews: And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures, Opening and alleging, that Christ must needs have suffered, and risen again from the dead; and that this Jesus, whom I preach unto you, is Christ." (Acts 17:1-3)
"Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever. For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away: But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you." (1 Peter 1:23-25)
No reasonable person who subscribes to Sola Scriptura would deny that there is a Christian church, and that there are ministers. So, it is foolish for De Maria to emphasize the role of teachers in the manner that he does. Sola Scriptura simply means that Scripture alone is the ultimate standard of authority in spiritual matters.
So what if the Bereans had only the Old Testament? The point which bears significance is that they still used Scripture as their standard of authority to test inspired apostles. The fact that Paul and Silas did not have a compiled New Testament in their hands is irrelevant. The fact that Jesus Christ was proven from the Old Testament to be the promised Jewish Messiah does not refute Sola Scriptura. In short, Catholic apologist De Maria has only raised a bunch of red herrings. Matters get even worse as one can pair Acts 17:11-12 with this text: