Wrong. Lumen Gentium teaches that baptism is the essential thing that makes Protestants member of the body of God. And the Lord's supper was never preached as the means of salvation by the NT church, contrary to Catholicism .
As said many times, the Church points to Scripture as the basis for this line in the sand, which must be flowed down through interpretations of Spirit-inspired men and women (tradition) (there’s no getting around the need for this - even the original languages are different).
Wrong. The Catholic church may invoke Scripture, but since in any conflict Scripture only consists of and means what she says, then her veracity is effectively the basis for any line in the sand, which premise of ensured veracity she imaginatively says Scripture supports.
For Rome presumed to "infallibly" declare she is and will be perpetually infallible whenever she speaks in accordance with her infallibly defined (scope and subject-based) formula, which renders her declaration that she is infallible, to be infallible, as well as all else she accordingly declares. Which is cultic, not Christian.
First point: I was speaking about what I would do to evangelize to a close loved one. I was trying to make this question real and everyday. Being real, I’d say that the Catholic Church has said that the 2 primary requirements for salvation that Protestants are missing, are Eucharist and Reconciliation. (We both require Baptism for example, and hold so many similar moral truths.) Look, its teachings focus on RISK; it’s certainly possible (and it goes without saying - desired!) that all the baptized are saved. It’s the risk, which is why I tried to write about the situation of trying to “save” (sorry, evangelize to) a close loved one - tried to stay out of theory (where being risky is fine).
Second point: With the language of an academic, you just restated my main point - The Church points to Scripture as its basis for its beliefs, whether or not you agree with that basis. The Church is also clear that is IS fallible on many issues, INCLUDING the Eucharist, by asserting the humble doctrine of Mystery. Although Mystery is a difficult concept for our prideful, scientific, post-Cartesian culture to grasp, I am sure that you and the many, many disparate Protestant sects do also say that you recognize where theological explanations must be imperfect, at best.
This last point applies to you earlier posts to me, though I apologize for not having time to read all of it yet. My quick takeaway from part of that is this question to you:
* Do you know what form God takes now in our material world?