St. Cyril of Alexandria was born about 380 in Alexandria and studied under his uncle Theophilus, Patriarch of Alexandria. Cyril made it his rule never to advance any doctrine that he had not learned from the ancient Fathers.
Speaking at a general audience in 2007, Pope Benedict XVI said, “Cyril was later defined as ‘the guardian of exactitude’ – to be understood as guardian of the true faith – and even the ‘seal of the Fathers.’ These ancient descriptions express clearly a characteristic feature of Cyril: the Bishop of Alexandria’s constant reference to earlier ecclesiastical authors (including, in particular, Athanasius), for the purpose of showing the continuity with tradition of theology itself. He deliberately, explicitly inserted himself into the Church’s tradition, which he recognized as guaranteeing continuity with the Apostles and with Christ himself.”
According Father Alban Butler, author of The Lives of the Fathers, Martyrs and Other Principal Saints, “[Cyril] had imbibed certain prejudices from his uncle against the great St. Chrysostom, but was prevailed on by St. Isidore of Pelusium, and others, to insert his name in the Dyptics of his church in 419, after which, Pope Zozimus sent him letters of communion.”
In 428, Nestorius became the Patriarch of Constantinople. He began to deny the unity of Person in Christ and to refuse the title of “Mother of God” for the Blessed Virgin.
People were scandalized and Cyril tried to correct Nestorius, writing him two letters explaining the mystery of the Incarnation and the unity of divinity and humanity in Christ. He wrote, “This does the declaration of the exact Faith everywhere set forth to us, thus shall we find that the holy Fathers thought, thus were they bold to call the holy Virgin Mother of God: not as though the Nature of the Word or His Godhead took a beginning of Being from the holy Virgin, but in that the holy Body souled with a reasonable soul was born of her, whereunto the Word united Personally is said to have been born after the Flesh.”
Nestorius refused to accept the teaching and hence Cyril denounced him to Pope Celestine. After examining the teaching of Nestorius in a council at Rome, Pope Celestine condemned it and pronounced a sentence of excommunication and deposition against Nestorius unless he publicly retracted.
Cyril was appointed Pope Celestine’s vicegerent and wrote a third letter to Nestorius, listing his 12 propositions with anathemas and requiring Nestorius to sign it as a proof of his orthodoxy. Nestorius refused to comply.
To resolve the matter, the Third Ecumenical Council was called at Ephesus in 431 to resolve the matter. Even tough Nestorius was in Ephesus, he refused to attend the council despite repeated summons. During the council, Nestorius was condemned for his teaching and deposed. The council upheld the title of the Blessed Virgin as “Mother of God.”
In the years following the council, Cyril devoted himself patiently and tirelessly to defending and explaining the true teaching. He died peacefully on June 27, 444. Pope Celestine praised him as “a generous defender of the Church and Faith and an apostolic man.” In 1882 St. Cyril was proclaimed a Doctor of the Church by Pope Leo XIII.
啟祿保衛瑪利亞為「天主之母」
聖亞歷山大.啟祿約在公元380年，出生於亞歷山大，受教於他叔父特奧斐勒斯，時任亞歷山大宗主教。啟祿規範自己永不促進那些非來自古教父的道理。教宗本篤十六世在2007年10月3日公開接見群眾時，評論他說：「啟祿後來被稱為『精確性的護衛』 ── 真信仰的守護者 ── 甚至被稱為『教父的封印』。這些古老的記載清楚地顯示啟祿的特徵：這位亞歷山大主教，常引用早期教會的作者（特別是聖達修），以顯示神學與傳統的連續。他故意把自己明確地納入教會的傳統，他視之為保證與基督和宗徒們連續。」
雅伯.畢勒神父說：「啟祿從他的叔父吸取了對偉大聖金口若望的偏見；然而，彼奈思諳的聖依西多等人，勸服他於419年把金口若望的名字，納入他教會的紀念名單裡。此後，教宗佐西向啟祿發出共融的信函。」
公元428年，聶斯多略任亞歷山大宗主教，卻發表反對基督天主性與人性的結合，進而否定聖母是「天主之母」，帶來眾人的震驚；啟祿立即設法糾正聶斯多略。
啟祿向聶斯多略發了兩封信，解釋「道成肉身」的奧蹟，和基督內的天主性與人性。啟祿指出：教父們的思維，無懼地認定至聖童貞為『天主之母』，非關聖言本性或天主，從至聖童貞取得開端；而是至聖之身具有靈魂和天主性，完全出自聖母之身。
遭到聶斯多略的拒絕，啟祿惟有上書教宗聖雷定一世。教宗在羅馬會議上，再三審視聶斯多略的主張，決定譴責他；命令他除非在收到通知後十天內撤銷主張，便罷黜他宗主教之職，並把他開除教籍。教宗聖雷定一世同時委派啟祿作副手，處理事宜。啟祿再給聶斯多略發信，力陳他十二點的異端理論和對它們的譴責，令他簽署否定這些異端理論，回歸正統。可惜聶斯多略堅拒照辦。
公元431年，厄弗所大公會議召開。雖然聶斯多略身在厄弗所，卻拒絕多次的傳召出席。大公會議決定譴責聶斯多略，把他開除，重申至聖童貞為「天主之母」。當時厄弗所宗主教偏於聶斯多略，但最後也確認正統教義，與啟祿和教會修好。
大公會議完畢後數年，啟祿仍繼續不辭勞苦、富有耐性地，守護著教會對真理的教導。公元444年6月27日安詳地去世。教宗聖雷定一世稱讚他是「一位對教會及信德的慷慨守護人，也是一位使徒的人」。1882年教宗良十三世奉聖亞歷山大.啟祿為「教會聖師」。
