The “doctrine” I was referring to in that context was the Orthodox understanding of the Eucharist as a propitiatory sacrifice. Regarding the Bible, I don’t consider what I said to be a matter of belief. It is mere history, that anyone can verify for themselves. The Church did exist for decades before a single book of the NT was written, and existed for several centuries before there were any authoritative declarations regarding the limits of the canon. It was early Church councils that decided what the canon is. The NT didn’t just fall directly from heaven. And until that time, the local Churches relied on whatever books of the NT they had in their possession, along with the authority of their bishop, early local creeds, and the traditional liturgy. To oppose 4th century statements about the Eucharist to the same Scriptures that were also canonized by the same generation of Fathers in the 4th century would have been incomprehensible in that era. That is the only substantive point I was making. What got canonized wasn’t just those particular books, but those books as they were interpreted and understood by the Church which canonized them.