Remember and understand well that where Peter is, there is the Church; that those who refuse to associate in communion with the Chair of Peter belong to Antichrist, not to Christ. He who would separate himself from the Roman Pontiff has no further bond with Christ.
Pope Leo XIIIThoughtful men, with hearts craving the truth, have come to seek in the Catholic Church the road which leads with surety to eternal life. They have understood that they could not cleave to Jesus Christ as the Head of the Church if they did not belong to the Body of Jesus Christ which is the Church. Nor could they ever hope to possess in all its purity the faith of Jesus Christ if they were to reject its legitimate teaching authority entrusted to Peter and his successors.
Pope Leo XIIIThese most crafty enemies [the devils] have filled and inebriated with gall and bitterness the Church, the spouse of the Immaculate Lamb, and have laid impious hands on Her most sacred possessions. In the Holy Place itself, where has been set up the See of the most holy Peter and the Chair of Truth for the light of the world, they have raised the throne of their abominable impiety, with the iniquitous design that when the Pastor has been struck, the sheep may be scattered.
Pope Leo XIIIIt is clear that the main tenet of socialism, community of goods, must be utterly rejected, since it only injures those whom it would seem meant to benefit, is directly contrary to the natural rights of mankind, and would introduce confusion and disorder into the commonweal. The first and most fundamental principle, therefore, if one would undertake to alleviate the condition of the masses, must be the inviolability of private property.
Pope Leo XIII