It is nice to make connections which show us how the Church was always alive throughout the centuries before our own time. Today is the feast of St. Pope Sixtus III, whom you will remember as having been involved with the "Liberian Basilica", more commonly known as St. Mary Major in Rome.
Pope Sixtus has an entry in the Roman Martyrology:
6. Romae via Tiburtina iuxta Sanctum Laurentium, depositio sancti Xysti papae Tertii, qui inter Antiochenum patriarchatum et Alexandrinum dissensiones composuit atque in Urbe beatae Mariae basilicam plebi Dei dedit in Exquiliis. … At Rome in the Via Tiburtina near (the Basilica of) Saint Lawrence (outside the walls) the Deposition (of the body) of Saint Sixtus III, pope, who resolved the disagreements between the Patriarchs of Antioch and of Alexandria, and gave to the people of God the Basilica of Blessed Mary on the Esquiline Hill.
In the entry I linked to above, about the dedication of S.M. Maggiore, there was dicussion in the comments afterward about the meaning of the Latin in the mosaic on the arch (which was overseen by the future St. Pope Leo I). Take a look at that.
Here is the old Catholic Encylopedia entry for Sixtus III (emphasis mine):
Consecrated 31 July, 432; d. 440. Previous to his accession he was prominent among the Roman clergy and in correspondence with St. Augustine. He reigned during the Nestorian and Pelagian controversies, and it was probably owing to his conciliatory disposition that he was falsely accused of leanings towards these heresies. As pope he approved the Acts of the Council of Ephesus and endeavoured to restore peace between Cyril of Alexandria and John of Antioch. In the Pelagian controversy he frustrated the attempt of Julian of Eclanum to be readmitted to communion with the Catholic Church. He defended the pope’s right of supremacy over Illyricum against the local bishops and the ambitious designs of Proclus of Constantinople. At Rome he restored the Basilica of Liberius, now known as St. Mary Major, enlarged the Basilica of St. Lawrence-Without-the-Walls, and obtained precious gifts from the Emperor Valentinian III for St. Peter’s and the Lateran Basilica. The work which asserts that the consul Bassus accused him of crime is a forgery. He is the author of eight letters (in P.L., L, 583 sqq.), but he did not write the works "On Riches", "On False Teachers", and "On Chastity" ("De divitiis", "De malis doctoribus", "De castitate") attributed to him. His feast is kept on 28 March.
Well… his feast is now today, not 28 March.
Hmmm… Sixtus corresponded with Augustine! Let’s see if we can find a letter. Yes, indeed, here it is. You see, Sixtus (before his ascent to the See of Rome) was thought to be a supporter of Pelagius. Augustine get’s into it with him in ep. 194 written in 418. Augustine had also written ep. 191 to him before. We probably need some background into the fascinating time in our family the Church’s history.
Ep. 194 was adressed to Sixtus, who was at the time a priest of the clergy of Rome. Sixtus would not be elected Pope until 432. Augustine wrote to Sixtus about Pelagian issues, since Sixtus was thought to be a sopporter of Pelagius. Augustine pressed Sixtus to silence and instruct these heretics and gave him some talking points about the absolute gratuity of the election of the predestined to salvation.
The issue of predestination and grace would be at the heart of the so-called "Semi-Pelagian" controversy. And it was this very letter, ep. 192 from Augustine to Sixtus, which eventually would spark a real controversy for the monks of Adrumentum in North Africa. One of the monks of Hadrumentum, Florus, found a copy of the letter in the library of Evodius the Bishop of Uzalis. Florus sent a copy to the monks back home in Hadrumentum and they got all riled up about predestination and grace. They were shocked by what Augustine was saying and concluded that, for example, there superior shouldn’t punish them if they didn’t pray or if they behaved badly, but should rather simply pray that God would give them the grace they were apparently lacking. The monks were wondering what good it was to pray, etc., if everything was predestined. These monks wrote to Augustine for a clarification about what he had written to Sixtus and the bishop responded to their abbot with two works, On Grace and Free Will and On Correction and Grace. (Augustine’s letters 214 and 215 have more on all this business.)
The letter itself ep. 192 starts with Augustine saying how happy he is that Sixtus was against the Pelagians. He distingushes the different types of Pelagians and how to deal with them. Some ought to be silenced and some instructed. He then says in a nutshell that because of Adam’s sin everyone deserves damnation. Through the Sacrifice of the Cross Christ’s merits and justification are extended to us sinners. Since non of us deserve grace on our own, we are justly damned, except for Christ’s merits. We cannot in ourselves merit even the choice of who will receive grace, either because of what we might have done in the past or what God foresees we will do in the future. God saves some out of mercy and He is just when people are damned. He uses the example of infants he die, some baptized and some not baptized. God foresees all outcomes and in mercy provides baptism for some and not for others. It is divine providence, not luck or fate or destiny outside of what God foresees. Similarly, God allows some who hear the Good News to convert and be justified, and to others he does not extend this grace. Even our prayers for mercy and our faith are graces. This is where we get the famous concept that God crowns his own merits in us.
Let us see some of ep. 194 from Augustine to Sixtus, later St. Pope Sixtus III.
18. … But we must confess that God helps us in one way before he dwells in a person and in another way when He dwells in a person. For, when He dwells in a person, he helps a person who is already a believer.
19. What merit, then, does a human being have before grace so that by that merit he may recieve grace, since only grace produces us us every good merit of our and since, when God crowns our merits, He crowns His own gifts?
Does that phrase about crowning his own gifts in us sound familiar? It ought to. It is in one of the new Prefaces, “de sanctis” – (De gloria Sanctorum), in the Novus Ordo Missale Romanum which in English is called the Preface "of Holy Men and Women":
Vere dignum et iustum est, aequum et salutare, nos tibi semper et ubique gratias agere: Domine, sancte Pater, omnipotens aeterne Deus: Qui in Sanctorum concilio celebraris, et eorum coronando merita tua dona coronas. Qui nobis eorum conversatione largiris exemplum, et communione consortium, et intercessione subsidium; ut, tantis testibus confirmati, ad propositum certamen curramus invicti et immarcescibilem cum eis coronam gloriae consequamur, per Christum Dominum nostrum. Et ideo cum Angelis et Archangelis, cumque multiplici congregatione Sanctorum, hymnum laudis tibi canimus, sine fine dicentes: Sanctus.