Let us give thanks to God the Father, through his Son, in the Holy Spirit, who, by reason of his great charity with which he has loved us, has taken pity on us; and whereas we were dead in sins, has quickened us in Christ to make us a new creation in him, a new handiwork. Let us accordingly lay aside our former way of life with all its works, and claiming our joint portion in Christ's sonship, let us renounce the deeds of corrupt nature. Recognize your dignity, O Christian, and once made a sharer in the divine nature, do not by your evil conduct return to the base servitude of the past. Keep in mind of whose head and body you are a member. Never forget that you have been plucked from the power of darkness and taken up into the light and kingdom of God. By the sacrament of baptism you have become a temple of the Holy Spirit. Do not through your depravity drive away so great a guest and put yourself once more in bondage to the devil, for the blood of Christ was the price of your redemption.
(Sermo 1 in Nativitate Domini 1-3: PL 54, 190-193.)
Bishop of Rome, St. Leo left many letters and sermons to attest to his teaching and preaching, chief among his writings being the Tome he sent to the Council of Chalcedon in 451, an articulation of the hypostatic union which the council hailed as 'the voice of Peter' for orthodox teaching.
ST. AUGUSTINE: Observe the Local Custom
When my mother reached Milan, she found the church there not fasting on Saturdays. She was troubled, and hesitated as to what she should do. I applied on her behalf to Ambrose for his advice. He replied, "When I go to Rome, I also fast on Saturday: when here, I do not. If you go to any church, observe the local custom."
-- Letter 54, 2
Prayer. Lord, while I was still far away from you, you coaxed me in a great many ways to hear you from afar and be converted to you and call upon you.
-- Confessions 13, 1
ST. FRANCIS DE SALES:
It is a very fine thing to feel ashamed of oneself when one realizes one's own imperfections and misery, but the feeling must not drag on lest one lose heart. It is necessary to raise the heart to God with a holy confidence, founded not in our strength but in God. We indeed change, but God never does; He always remains equally good and merciful toward us, whether we are weak and imperfect or perfect and strong. I always say that our misery is the throne of God's mercy, and so we must realize that the greater our misery, the greater should be our confidence in Him.
(Spiritual Discourses II; O. VI, p. 22)
I HAVE only that which the poor have equally with the rich; which the lonely have equally with the man of many friends. To me this whole strange world is homely, because in the heart of it there is a home; to me this cruel world is kindly, because higher than the heavens there is something more human than humanity. If a man must not fight for this, may he fight for anything? I would fight for my friend, but if I lost my friend, I should still be there. I would fight for my country, but if I lost my country, I should still exist. But if what that devil dreams were true, I should not be––I would burst like a bubble and be gone; I could not live in that imbecile universe. Shall I not fight for my own existence?
('The Ball and the Cross')