However, by fixing the entire scope of the message to the canon alone, sola scriptura Protestants “freeze” it, making it a single, definite data set. They can then mine it for patterns and subtleties while acting upon the assurance that it cannot ever change: their interpretations can, but they can rest in the assurance that the text remains fixed.
OK. However, scripture was not “fixed” for hundreds of years after the apostles walked the earth. What did those early Christians rely on: scripture as we know it today (codified and bound) or the Church?
Replacing that with “God speaking through the Church” is, from their perspective, tantamount to replacing a single voice with a cacophony.

All churches, including the CC, in terms of leadership, are viewed as a cacophony, necessitating the exclusive trust in scripture alone? OK. How would they interpret John 16:13 and John 14:16, as it relates to either the church or each baptised person, as he or she is guided by God?
I suppose, based on that, the Holy Spirit as per scripture is not guiding Jesus’ church into all truth i.e. the trustworthiness of God speaking through Jesus’ Church is not to be trusted. OK.
Catholicism believes that there is a single underlying voice in correct Catholic teaching, but “correct” is defined there with reference to a historical consensus, and so even to start to identify that voice requires a complete knowledge of the whole history of Catholic theology (q.v. the disagreements within Catholicism about the sum total of what has been pronounced ex cathedra).
So you (or they) are suggesting that not only has God failed to guide Jesus’ Church into all truth - God also failed in another way, due to the fact that doctrinal disagreements within the Catholic Church abound? Every Catholic must defer to the Magisterium vis-a-vis doctrinal matters.
Since Catholics continue to speak, that consensus continues to develop, making the problem of identifying coherence yet more problematic.
They would have to provide proof and the only way to do so is for them to defer to sacred scripture, interpret it for themselves, and compare their interpretation/understanding to the CC’s interpretation/understanding, resulting in beliefs contrary to the Catholic church, but as you mentioned - that won’t work because, although the text can be trusted, the interpretation cannot.
In essence, you are asking them to believe in more than they already do (adding your Church to their Bible…
I would never ask them to add the CC to their bible. What about the leaders in their church preaching and teaching? After all, all churches subscribe to certain beliefs that must be adhered to - right or wrong i.e. if the bible is the only thing to be trusted, then why the need for church leaders?
- and imagine how you would respond to a Muslim who told you that you needed to use Islamic theology to understand your Bible), while they shall also be understanding less (because the volume of data which they shall need to process is greater). That works in Catholicism because the responsibility for the knowledge is (via that extra belief) displaced onto the Church, but Protestantism is a much more individualised ideological system, and it is difficult for independently-minded people to surrender that independence.
So, to capsulize: we have a bible that can be trusted, but no way to discern the truths therein, due to the fact that interpretations cannot be trusted due to change, as per you opening statement: “They can then mine it for patterns and subtleties while acting upon the assurance that it cannot ever change: their interpretations can, but they can rest in the assurance that the text remains fixed.”
In short, you are asking them to do something tremendously radical (i.e. expensive in terms of energy), and you would need to convince them that it is hugely profitable if you are going to have any hope of persuading them.
Nah. I am asking them to do as scripture says vis-a-vis Jesus’ church, trusting that the Holy Spirit is guiding Jesus’ church into all truth, and it’s there job to locate what they believe to be, Jesus’ church; that’s it. The bible as the Christians sole rule of faith is unbiblical, so why should they accept/embrace it?
