There's a glaring error in that statement. Catholicism is not in and of itself a denomination. Since it is the Church Christ instituted, other Christian sects arose from it. Thus, the "types" of Christianity are merely variations of the original, the Catholic Church, and must be denominations.
No doubt the Arian heretics who were slaughtered by the millions when Iz Lame spread were sure they were correct as well and it's just a coincidence that Iz Lame was stopped at almost exactly limits of the spread of the Arian. Likewise, there are probably people who can't grasp the fact that God Himself slaughtered Core for exactly the same thing Protestantism teaches. Others, though, clearly understand that they're following heresy and play little games to feed their ego and deny the obvious which is that they're so dedicated to Self Worship that they cannot accept Christ placing anyone in authority over them.
No Priesthood, no sacrifice. No sacrifice, no salvation. That's the simple Truth of Scripture from beginning to end and Christ left His Church with a Priesthood that through the power of the Holy Spirit enables us to partake of the Eucharist which is the final and ongoing sacrifice.
This nation is clearly suffering due to being dedicated to what Jude explicitly warned against and yet those Jude calls clouds without rain can't understand why they're not bearing good fruit and continue to fragment. Seeing such folks argue that more of the same thing they've been doing will turn things around would be halarious if it wasn't so sad. Regards