Philosophical and Practical Problems with Sola Scriptura

What should the Protestant do? If his denomination represents a valid ecclesiastical authority, he should submit. If it does not, he should not. But how does he know? The answer to the question “Which religious authorities are valid?” cannot be “Those whose doctrines are biblical,” because that is exactly what is under dispute. This would be as redundant as saying: “The only biblical leaders are those who are biblical.” While this is true, it is tautologous and unhelpful; since it offers no guidance in identifying what is “biblical.” The Lutherans say that their doctrines are biblical, as do the Methodists, Presbyterians, Pentecostals, Baptists, Nazarines, Mennonites, Moravians, Plymouth Brethren, Seventh Day Adventists, and Disciples of Christ—and Catholics. “Lord, to whom should we go?”
In the final analysis, there would seem to be no more than a couple of alternatives: either we are left with nothing but personal opinion, illumined as it may or may not be by private interpretations of others—which means it comes down to this: every man for himself, interpreting Scripture as best he can and joining whatever group or denomination agrees most closely with his personal understandings; or God has established some kind of identifiable authority, with a promise of protection against error, to guide the Church—so that we may trust that the religious authority to whom we defer is delegated by Christ in the same manner as those to whom He said “He who hears you hears me” (Lk 10:16), permitting us to reply to this authority with Peter’s words: “You have the words of eternal life” (Jn 6:68).