Not wanting to say anything against the OPC, of course they would say they follow the Bible.
I've felt the horns of the dilemma you are facing. There are two parts to the solution I came to.
First is that the Catholic Church can appear to be un-Biblical but I have found that to be on a superficial level only. Deeper down I have found it crazy how the deeper I have gone into Scripture the deeper the coherence between the Bible and the Catholic Church. My basic advice on that is to not take the easy answer and always be willing to dig deep. You may be pleasantly surprised.
The second part is to understand that Scripture did not fall from heaven but was written by the Church.
Protestants, if they are honest, accept the consensus on the Church Fathers on which books should be in the New Testament, They reject the consensus of those same Church Fathers on what books should be in the Old Testament. If they are honest they also would admit that they follow the Fathers on things like the Trinity. The surprising little secret is that Arius was the Sola Scriptura guy of his times, and it confirmed him in his own little heresy.
Everybody has traditions. Some have the tradition of vehemently saying they follow Scripture alone while they actually follow other things they aren't even aware of. The realistic thing is to accept that everybody follows traditions and to concentrate on which traditions actually make sense. And that gets to authority. Who has the authority to speak for the Church? Is everybody who has a Bible equal in authority? Or is it a session. whoever appointed them? Or were the Fathers right about apostolic authority?
The upshot is that the OPC is probably better than most groups. And that there is always some chaos in Catholic circles. But that tying up your raft to the barque of Peter can be the sanest, the most intellectually satisfying, and the most faithful thing to do. If you do so you will get criticism. You might even be expelled by the people you have been hanging out with. So be sure of yourself, be sure of your facts, be sure of what the Lord wants of you.
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