Whoever, then, thinks that he understands the Holy Scriptures, or any part of them, but puts such an interpretation upon them as does not tend to build up this twofold love of God and our neighbor, does not yet understand them as he ought.
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.
AugustineThe wounds of a friend are better than the kisses of an enemy. To love with sternness is better than to deceive with gentleness.... In Luke [14:23] it is written: "Compel people to come in!" By threats of the wrath of God, the Father draws souls to his Son.
Therefore once for all this short command is given to you. 'Love and do what you will.' If you keep silent, keep silent by love; if you speak, speak by love; if you correct, correct by love; if you pardon, pardon by love: let love be rooted in you, and from the root nothing but good can grow.
Be always displeased with what you are if you wish to be what you are not. Always add, always walk, always proceed. Neither stand still nor go back nor deviate.
What is held by the whole Church, and that not as instituted by Councils, but as a matter of invariable custom, is rightly held to have been handed down by authority.