Our Blessed LORD rebuked the Scribes & Pharisees, referring to them as "sons of the Devil," but never incited disrespect, rebellion or separation from their Divine Office ("Cathedra"-Seats of Authority).
The saints seem pretty consistent in submitting to the discipline of superior regardless of the latter's misunderstanding or motives. They never gave up what they believed is true or moderated their tone, it so seems. Louis Marie DeMontfort did not lose his fire, devotion to the BVM or seeking after the abject souls to save.
Is this also true of an anti-pope?
I think we keep our respect for him. But if he teaches false doctrines we can't obey. But still keeping the respect. He is called Holy Father for a reason. GOD Wishes it to be so. So we obey GOD.
Love him, respect him but refuse his false doctrines and teachings. That's the best way I can explain it.
However there is a story of Padre Saint Pio who obeyed a Pope even though he knew the Pope was wrong. All I know is this is why I avoid most scandals on our Priests and religious. I don't want to get caught up into the anger the posts seem to stir in the people nor the hate I read from them. I think it's best to avoid anything at all bad about them and what they are doing. Our business is to pray for them. Not judge nor condemn which Saint Catherine is saying.
This is extreme phrasing (“even if the Pope were Satan incarnate…”) and is almost certainly exaggerated or later stylized language, not a precise historical quote.
St. Catherine of Siena on Authority, Obedience, and Truth
“Even if the Pope were a devil incarnate, we ought not to raise our heads against him, but rather to lie down in rest on his bosom.”
Source: Letter T74, To the Florentines. Wording varies slightly across translations of her Letters.
“He who is obedient to you is obedient to me, and he who despises you despises me.”
Source: The Dialogue of St. Catherine of Siena, Treatise on Obedience.
“Be a manly man, and not a timorous child.”
Source: Letter to Pope Gregory XI.
“I tell you, on behalf of Christ crucified, that you should no longer be negligent, but come and take possession of the place of the glorious Shepherd St. Peter.”
Source: Letter to Pope Gregory XI.
“The sins of bad pastors are the cause of the ruin and loss of souls.”
Source: The Dialogue of St. Catherine of Siena.
Summary
St. Catherine of Siena teaches reverence for the office, obedience rooted in Christ, and courageous truth spoken without contempt.
One more comment from Fides Et Ratio
Do not despise the office.
Do not flatter the man.
Speak the truth in charity.
Remain in the Church.
This is actually true in spirit, but incomplete and slightly risky if left alone.
Catherine was ferocious toward sin and error
But not reckless toward authority
And not contemptuous toward persons
How can we lay down on the bosom of Satan, a rebel against our Father, and not by association rebel against our Father? God himself tells us His sheep hear the voice of the Shepherd and follow Him. They do not hear the voice of a stranger.
And why I was so upset when people who call themselves Catholic actually went wild when trump a prot a great sinner was dressed like a Pope. That was a grave sin to think it was so great. No less to constantly say he is more Catholic than other Catholics or worse, More Catholics than our Priests. I don't understand what they don't understand about the title of "HOLY FATHER". That was a grave sin and still they defend the meme and trump doing that and other evil things he does daily. I still think about that. And it still breaks my heart and upsets me for Our Lord. Our Faith is nothing to joke about. EVER for ANY reason.
Our Lady of LaSalette said, two worm ridden POPES! Read what St. Catherine of Siena said again. And think what Our Holy Mother said. She didn't say, two worm ridden pretenders or fakes. Or men pretending to be Popes. But POPES!
Our Lady of LaSalette?
“Marie-Julie Jahenny … stated that there would come two popes, one that would follow the other, that would lead the Church in a false direction,” the author said.
“The Blessed Virgin Mary, amongst so many other shocking revelations, stated that the day would come when there would be ‘deux papes vermollus’ in French, which in English … translates as ‘two worm-ridden popes’ succeeding one or the other".
Doubtful but still Popes. Bad Popes. But still Popes. Doubtful meaning: lacking a definite opinion, conviction, or determination
uncertain in outcome: undecided.
giving rise to doubt or uncertainty : open to question.
I think The Blessed Mother meant us. We would be doubting and uncertain. But it still seems they are still Popes in the Eyes of GOD. Because GOD never has doubts or uncertainly. Makes sense?
"Je n'ai pas vu, je ne vois pas de Grand Pape et de Grand Monarque avant une grandissime tribulation, épouvantable, terrible et générale pour toute la chrétienté. Mais, avant ce temps, il y aura deux fois une paix de peu de durée, deux papes vermoulus, plats, douteux."