"No Room For Private Judgment" Says Blessed John Henry Newman

"Immediate, implicit submission of the mind was, in the lifetime of the Apostles, the only, the necessary token of faith; then there was no room whatever for what is now called private judgment. No one could say: "I will choose my religion for myself, I will believe this, I will not believe that; I will pledge myself to nothing; I will believe just as long as I please, and no longer; what I believe today I will reject tomorrow, if I choose. I will believe what the Apostles have as yet said, but I will not believe what they shall say in time to come." No; either the Apostles were from God, or they were not; if they were, everything that they preached was to be believed by their hearers; if they were not, there was nothing for their hearers to believe. To believe a little, to believe more or less, was impossible; it contradicted the very notion of believing: if one part was to be believed, every part was to be believed; it was an absurdity to believe one thing and not another; for the word of the Apostles, which made the one true, made the other true too; they were nothing in themselves, they were all things, they were an infallible authority, as coming from God. The world had either to become Christian, or to let it alone; there was no room for private tastes and fancies, no room for private judgment."   John Cardinal Henry Newman (convert from Anglicanism in the 19th century)

When I first returned to the Catholic faith, I explained to a friend that the teaching of the Eucharist (the real body and blood of Christ) was  from the beginning what the Church believed, and therefore I believed it was true. My friend said, "well we don't believe that" which ended the discussion.
At the time, it wasn't appropriate to pursue the argument, but I think back to how this is how many of us protestants chose a church. "Let's go to one that believes what I believe because there are certain things I have come to believe and certain things I have rejected." This was for the most part not based on historical evidence or what early Christians closest to the apostles believed.  For the past 500 years Christians have come to believe that they can pick and choose their religion based on their own private judgment. It started with Luther but soon everyone was assuming they were now "apostolic" and could decide what to believe given that they were no longer under the  mantle of Christ's Church. This was not the ancient way as John Cardinal Newman explains.