The Old (Testament) is in the New (Testament) revealed, the New is in the Old concealed.

Do not follow any road, but that which Christ trod. This road seems hard, but it is safe.

Although among heretics and schismatics there is the same Baptism, nevertheless, the remission of sins is not operative among them because of the very rottenness of discord and wickedness of dissension ... Baptism was in them, but it did not profit them outside the Church ... Outside the Church, Baptism works death because of discord.

Without God, man cannot, and without man, God will not.

You have enemies. For who can live on this earth without them? Take heed to yourselves: love them. In no way can your enemy so hurt you by his violence, as you hurt yourself if you love him not.

The one who sings, prays twice.

As to those other things which we hold on the authority, not of Scripture, but of tradition, and which are observed throughout the whole world, it may be understood that they are held as approved and instituted either by the apostles themselves, or by plenary Councils, whose authority in the Church is most useful, e.g. the annual commemoration, by special solemnities, of the Lord's passion, resurrection, and ascension, and of the descent of the Holy Spirit from heaven, and whatever else is in like manner observed by the whole Church wherever it has been established.