To the OP, John, I’m so glad you’re struggling with the issue of authority. I think it shows some deeper thinking on your part. I am a revert, back in the church after many years outside of it.
When I began re-investigating Catholicism and its differences from evangelicalism, issue by issue, I always - ALWAYS - found myself (in a sense) having dug through the specific issue to the deeper issue of authority.
So often on an issue I’d encounter two opposing but both solid sounding arguments. Which raised the question in me, which one to believe? Which raised another question. Did God leave his church, and all his people, his sheep, shepherd-less? When a difference of opinion exists between two honest seeking believers, and those two points of view are incompatible with each other, did God really leave individual believers alone to drift to one side or the other? In the end, I could no longer believe in this shepherd-less church model.
The only church with a legitimate claim to this mantle of authority is the Catholic church.
I’ve also thought it would be unconscionable of God to leave humanity shepherd-less in the long years before the invention of the printing press.
So for me it’s not like I found one or two or five scripture verses that convinced me the Catholic Church had this authority from God. Nor did I accept its authority because I ended up understanding and agreeing with the Catholic position on every issue. I just could no longer accept a world without a church with that authority.
I also realized that accepting the authority of the church would mean me very specifically bowing my knee, and my intellect, on certain issues that I still had with the Catholic view of things. But the positive side of that, is the sense that the faith is so much bigger than me, so much bigger than just my mind. And I like the extra dose of humility it pushes me to.
God bless you John.