Anyone can make a claim, that is true. But there is only one Church that can back up that claim; one Church that can trace itself historically clear back to Peter and therefore to Christ himself, and only one Church that has kept the same doctrines since the first century and can prove it. You should do a little reading from the early Christians. They were Catholic.
Kept the same doctrines… like penance? In the early church penance could only be done once in a lifetime. Or like veneration of icons? At the 2nd Council of Nicea in the 8th century, they only produced
one example from the first 3 centuries in support of the practice. And that example was in a pagan context, not Christian. Do you suppose Paul prayed the rosary, or celebrated holy days of obligation under penalty of mortal sin and eternal damnation? Do you suppose the early church fathers’ rule of faith was Rome’s teaching, or did they think Scripture was formally sufficient?
These are quotes from John Chrysostom (my emphasis added) which you may verify at your leisure:
“
But what,” say they, “if we do not understand the things we read?” Even if you do not understand the contents, your sanctification in a high degree results from it. However, it is impossible that all these things should alike be misunderstood;
for it was for this reason that the grace of the Holy Spirit ordained that tax-gatherers, and fishermen, and tent-makers, and shepherds, and goatherds, and uninstructed and illiterate men, should compose these books, that no untaught man should be able to make this pretext; in order that the things delivered should be easily comprehended by all—in order that the handicraftsman, the domestic, the widow, yea, the most unlearned of all men, should profit and be benefited by the reading. For it is not for vain-glory, as men of the world, but for the salvation of the hearers, that they composed these writings, who, from the beginning, were endued with the gift of the Holy Ghost.
and
For those without—philosophers, rhetoricians, and annalists, not striving for the common good, but having in view their own renown—if they said anything useful, even this they involved in their usual obscurity, as in a cloud.
But the apostles and prophets always did the very opposite; they, as the common instructors of the world, made all that they delivered plain to all men, in order that every one, even unaided, might be able to learn by the mere reading.
and
But, you say, Philip is not present with us now. Still, the Spirit that moved Philip is present with us. Let us not, beloved, neglect our salvation! “All these things are written for our admonition upon whom the ends of the world are come,” (1 Cor. x. 11).
The reading of the Scriptures is a great safeguard against sin; ignorance of the Scriptures is a great precipice and a deep gulf; to know nothing of the Scriptures, is a great betrayal of our salvation. This ignorance is the cause of heresies.
This is not a man saying “believe Rome” (which wasn’t a viable source of guidance in the 5th century as it didn’t have the centralised authority it has now. Rome simply couldn’t address the whole church, which you’ll find is a criterion for
ex cathedra infallible guidance) or even, “believe whatever I say”. The rule of faith was Scripture alone. That changed.
Telling me to “do a little reading” is presumptuous and
ad hominem.