Let me just stop you for a minute here.
Granting Peter’s investiture by Jesus with a leadership role in the Church, and even granting his status as the First Bishop of Rome, it is not a necessary corollary that the Pope is the successor of Peter as leader not only of the Roman See, but of the entire Church. We need to indulge some assumptions in order to get there. As best I can tell, when it comes to Peter’s passing on the Keys to the Kingdom to a single successor in Rome, and that successor to the next, and so on in an unbroken line of Roman bishops right down to Francis, the required assumptions are as follows:
1. Jesus intended Peter’s preeminent authority to be passed on after Peter’s death, i.e., it was intended as an
assignable authority. (No recorded words of Jesus, apocryphal or not, express such an intention.)
2. The means by which Peter’s authority got assigned – to one man only – was by
Peter’s own selection of a successor, and not by any wider apostolic vote (such as the election of Matthias as recounted in Acts 1:24-26).
3. Like Paul before him, Peter went to Rome to end his days in a church he did not found. But because of his preeminence, Peter – not Paul – became Rome’s bishop (unlike in Jerusalem, where James was leader of the church while Peter was active there).
4. Of all the bishops that Peter may have appointed in his travels (e.g., Antioch), the one man that he assigned his “keys” to was the bishop he appointed
in Rome, generally assumed to be Linus, per John Chrysostum’s
Homily 10 on Second Timothy (“This Linus, some say, was second Bishop of the Church of Rome after Peter”), but possibly Clement, per the
Epistle of Clement to James).
5. Peter’s authority not only could be assigned to another, but the assignee himself could
further assign that authority to a person of
his choosing, i.e., the “keys” are assignable by any subsequent recipient of those keys.
6. Eventually – likely to fill a gap when, inevitably, no one had been appointed as a successor before the incumbent died – the Bishop of Rome was installed not by his immediate predecessor but by acclamation of the Christian community in Rome, or by consensus or vote of clergy or of other bishops (in
Italy, not worldwide, for most of its early history) – all with the same validity as if appointed by his immediate predecessor.
It could be that each of these assumptions is supportable -- but they would have to be supported outside of Scripture, for Scripture doesn't tell us. I'm certainly not a
sola Srciptura guy, so I'd be fine with any other support for these assumptions that you can adduce here. But at least let's be honest:
these are the assumptions one must make in order to hold that "Jesus Christ established the papacy."
