When Our Lord Jesus Christ declared in the Gospel that they who were not with Him were His adversaries, He did not specify any particular kind of heresy, but pointed out everyone whomsoever who were not with Him and who, not gathering with Him, scattered His flock as being His adversaries ... Thus, neither did the blessed Apostle John distinguish anyone heresy or schism, nor set down anyone in particular as separatists, but gave to all who had gone out of the Church, and who had acted against the Church, the name of Antichrists ... Whence, it appears that everyone who is clearly known to have withdrawn from the charity and unity of the Catholic Church is an enemy of the Lord and an Antichrist.
They alone have remained outside the Church who, had they been inside, would have had to be cast forth; neither does the Lord permit the wheat to be swept away from His threshing-floor, but only the chaff alone can be separated from the Church.
Outside the Church there is no salvation.
The devil does not trouble himself with those whom he has already made sure of, nor does he labor to conquer those already in his power. Whomever he has already alienated from the Church, he overlooks and passes by without considering them worth his notice.
The Spouse of Christ cannot be defiled; she is incorrupt and chaste; she knows only one home ... It is she who rescues us for God, she who seals for the Kingdom the sons she has borne. Whoever is separated from the Church is joined to an adulterous union, and cut off from the promises made to the Church. He who has abandoned the Church of Christ shall not come to the rewards of Christ: he is a stranger, a worldling, an enemy. He cannot have God for his Father who does not have the Church for his Mother. If there was escape for anyone outside the Ark of Noah, then there is for one found to be outside the Church. Our Lord warns us when He says: "He who is not with Me is against Me, and he who gathers not with Me scatters" (Luke 11:23). Whoever breaks the peace and harmony of Christ acts against Christ; whoever gathers elsewhere than in the Church, scatters the Church of Christ ... He who does not keep this unity does not keep the law of God, does not hold the faith, and does not save his soul. This holy mystery of oneness, this unbreakable bond of close-knit harmony, is portrayed in the Gospel by the cloak of Our Lord Jesus Christ which was not divided ... That man cannot possess the garment of Christ who rends and divides the Church of Christ ... Can anyone, then, be so wicked and faithless, so insane with the madness of discord, as to believe it possible that the oneness of God, the garment of the Lord, the Church of Christ, should be divided, or dare to divide it himself? ... Do you think that a man can hold his own or survive, when he leaves the Church and sets up a new place and a separate home for himself? ... How can a Christian breast harbor the fierceness of wolves and madness of dogs and deadly venom of serpents and bloodlust of wild beasts? It is a blessing when such men break away from the Church!
Christ has declared the unity of the Church. Whoever parts and divides the Church cannot possess Christ ... The House of God is but one, and no one can have salvation except in the Church.
There is no salvation outside the Church.
He who does not keep to the true way of salvation will inevitably falter and stray; caught. up by some gust of error, he will be tossed about like windswept dust; walk as he may, he will make no headway towards his salvation.
There is no salvation outside the Church ...and it is they who in His Church have labored in doing good works whom the Lord says shall be received into the kingdom of Heaven on the Day of Judgment.
There is no Holy Ghost outside the Church.
This is He: our God! Not the God of all men, but of the faithful!