You are absolutely correct, I didn’t mean to imply that Baptism was unbiblical or even that baptism as a sacrament was unbibilical. I apologize for that.
You are also correct that no one who claims infallible authority agrees – including the pope.
Let’s not over-use the term. I, myself, admit that I am guilty of that here. “Infallibility” is a specific term the Church uses when She is describing the protection from error, given by the Spirit of God, when the governing and teaching authority in Rome is declaring a truth regarding faith and morals from the seat of Peter. This declaration need not be directly related to an interpretation She is making from Sacred Scripture. Infallibility has always existed since the apostolic charism of protection was given at Pentecost, but was publicly declared and officially defined only a relatively short time ago.
When I use infallible to describe the interpretation of Scripture, I mean it in a sense that Rome is protected by the Spirit from error when formulating and officially declaring doctrine regarding faith and morals as those doctrines are understood to be found within the writings of Scripture. The overwhelming majority of those doctrines have been declared during the apostolic age, given to The Church as the sacred deposit of faith.
On these officially doctrinal matters specifically of faith and morals, there is no disagreement within the Church, lest the one in disagreement and attempting to act on that disagreement be anathema. And there is no possibility of anyone ever changing doctrine of faith and morals, as the Spirit will not allow it to be done.
Now, as for Sola Scriptura, insofar as anyone who holds to that supreme authority of Scripture, and makes a public declaration of doctrine regarding faith and morals as taken from the pages of that supreme authority, no one can claim infallibility on those doctrines they’ve formulated. And if they do claim it, it is quickly revealed that there is no universal agreement with the body of believers (the “church”) that those indeed are the inerrant doctrines of the faith. And since we don’t see the claim of infallibility when declaring these doctrinal “truths” from Scripture, we must presume that these alleged doctrines are in error, or simply a matter of personal opinion.
What I’m waiting for is an individual who clings to SS to tell me that their doctrinal interpretations of Scripture are indeed infallible. Until then, I tend to not worry about their “opinions” of what Scripture reveals to them. Oh, perhaps I’ll still engage in showing them their errors, as I am confident in the Church’s Spirit-protected interpretations, but ultimately even that is an exercise in futility, because the crux of the issue does not revolve around a spat over this doctrine or that doctrine, but does revolve around the claim to be 100% correct when declaring doctrinal truths. If you allow for the fact that you are not 100% correct, protected by the Spirit in your doctrinal declarations, then what are you telling us with regard to supreme authority of Scripture? You’re telling us that that supreme authority may be in error…and hence, capable of leading us astray - a very critical, eternal-life altering notion.