The lesson is "do not become so proud that you think you are gods". and a connected lesson is "do not think your opinions are so good that they are the voice of God". These are simple lessons but people do not learn them.
Claiming to have sole and exclusive "all truth" as a religious organization comes with a bit of a logical conundrum.
All truth is inclusive of only seeing in part, 1 Cor. 13:12.
So any said group claiming to have and contain all truth is technically already defeated by the seeing only in part portion it would seem, if they were encompassing "all truth." It's a bit of a dilemma the RCC has gotten themselves into, even within older orthodoxy in general.
The open evidence of this basic failure to grasp the fact of the most obvious element of human existence that is universally known to all mankind, that "nobody is perfect, our Lord excepted" is shown by these vast groups of well learned men, technically claiming to contain and have exclusive rights to the realm, can't even work out the modifications of agreements in the filioque after literally centuries. And I'm banking it will never happen.
We could start the pile on this basis, but needless to say, no collective of sinners is going to be sinless. Large centralized organizations often prove to be fatal to the masses, religious or political, precisely for this basic flaw.
Now how could anyone sit in the infamous chair, having evil present within them and within all of the members affirming, say they are, what is that term again? Oh yeah, infallible.
No thank you.
Honesty would be a GREAT place to start for unity.
It's just hard to buy into twisted logic no matter who is trying to sell it it or how great their silk robes and fancy hats are, again, religious or political.
Better to remain fragmented, as the 7 churches of Rev. all had their obvious issues. lest evil present coalesce. We've had our lessons at that well long enough too.
The claims of if y'all would only agree with "us" then everything would be fine is just another lie as well.
As the writer of Hebrews rightly stated, "for finding fault with them." hasn't changed. The final matter of faith is our HOPE of Perfection. An earnest deposit is not full payment. Again, how can we claim said HOPE while claiming "all truth," which is supposedly in harmony with Godly Perfection, yet still hope for same? Hope will disappear when The Perfect comes and not a day sooner.
For some odd reason I distrust anyone who says you MUST obey only me if that claimant is not Perfect. And even if so, could I really follow and obey if I were not the same? Nope.
I'd suggest the only unity the churches DO have is our imperfections and infirmities. Now sort that one out. Maybe we should glory in them as Paul suggested?
Would any of us today listen to a man, Paul for example, that admitted to having an onslaught of concupiscent thoughts, who claimed to do evil, to have evil present with him, who claimed to have a messenger of Satan in his own flesh and is the present tense, "I am" chief of sinners?
Most would run out of the doors holding their hands over their ears. People will NOT listen. They can not.
Pre-ordained, in prep, waiting obviously for the real final solution from our Father