You didn’t find the assumption of Mary in that response.
The apostle Paul says: “Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle” (2 Thessalonians 2:15, KJV)
This is some biblical evidence for the importance of holding non-biblical (i.e. non-epistle) beliefs.
you are a “sola scriptura” believer, want to take a crack at post #492, something tells me you will extend the baptist lead to 3-0? where are the lutherans??