Protestants like to cherry-pick the Bible, cherry-pick St Augustine and even cherry-pick one of their heroes, Martin Luther.
It’s free for all for them.
No cherry pick, it is interesting you establish the RCC legitimacy based upon its own statements, just like the Muslims who according to the RCC Catechism worship the ‘One True God’. Lotta housecleaning at the RCC starting at the top with the ‘Vicar’.