The Shield of the Trinity

Gospel Reflection for June 15, 2025, Trinity Sunday - John 16:12-15

Jun 15, 2025

I have yet many things to say to you: but you cannot bear them now.
But when he, the Spirit of truth, is come, he will teach you all truth. For he shall not speak of himself; but what things soever he shall hear, he shall speak; and the things that are to come, he shall shew you.
He shall glorify me; because he shall receive of mine, and shall shew it to you.
All things whatsoever the Father hath, are mine. Therefore I said, that he shall receive of mine, and shew it to you. (John 16:12-15 DRA)

Today is the Solemnity of the Most Holy Trinity, one of the greatest feasts of the Church celebrating the central mystery of our faith, namely that God is both three and one, three divine Persons subsisting in one consubstantial nature, sharing all things but numerically distinct by their opposed relations alone. This dogma separates Christianity from all other religions and unites all Christians who are validly baptized according to the Trinitarian formula given by Our Lord. (Mt 28:19)

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For this reflection, I would like to focus on a treasure of Tradition which, like many, has sadly fallen into disuse. Even before Vatican II, it had already been reduced by St. Pius X to Sundays after Epiphany and Pentecost and Trinity Sunday for Mass and in the Divine Office hour of Prime, while the 1960 reform then further limited its use to only once a year, on Trinity Sunday. Since the implementation of the Novus Ordo, it has disappeared almost entirely.

This treasure of Tradition is known as the Athanasian Creed, also called the Quicumque Vult for its first words, “whosoever will be saved.” It also became known as the Shield of the Trinity for its triangular illustration of Trinitarian doctrine. Medieval Christians most often attributed it to St. Athanasius of Alexandria, which is possible, but due to certain factors, such as its having been written in Latin (at least in our earliest records) and dealing with certain issues slightly later than the Alexandrian patriarch, as well as recent documentary discoveries, it is now attributed most probably to St. Vincent of Lérins or one of his students in southern Gaul. Due to its power in refuting the errors of Arius and other anti-Trinitarian heretics, it became widely popular soon after its composition, and in the Age of Faith it was treated as a third creed to recite at Mass.

The Athanasian Creed systematically and liturgically spells out the Tradition of the Church on the Blessed Trinity and, like the original Nicene Creed, also includes anathemas against errors violating its doctrines. For this Trinity Sunday, it would be a fruitful exercise to read it slowly and carefully, contemplating the profundity of the mystery at the very heart of our faith which we celebrate today and which, since it “surpasseth all understanding,” (Phil 4:7) can only be accepted in submission to God’s divine authority through the enlightenment of grace. When read by a modern Catholic, it also offers a refreshing clarity, severity and applicability to which we have become all too unaccustomed:

Quicumque vult salvus esse, ante omnia opus est, ut teneat Catholicam fidem: Quam nisi quisque integram inviolatamque servaverit, absque dubio in aeternum peribit. Fides autem Catholica haec est: ut unum Deum in Trinitate, et Trinitatem in unitate veneremur. Neque confundentes personas, neque substantiam separantes. Alia est enim persona Patris alia Filii, alia Spiritus Sancti: Sed Patris, et Filii, et Spiritus Sancti una est divinitas, aequalis gloria, coeterna maiestas. Qualis Pater, talis Filius, talis [et] Spiritus Sanctus. Increatus Pater, increatus Filius, increatus [et] Spiritus Sanctus. Immensus Pater, immensus Filius, immensus [et] Spiritus Sanctus. Aeternus Pater, aeternus Filius, aeternus [et] Spiritus Sanctus. Et tamen non tres aeterni, sed unus aeternus. Sicut non tres increati, nec tres immensi, sed unus increatus, et unus immensus. Similiter omnipotens Pater, omnipotens Filius, omnipotens [et] Spiritus Sanctus. Et tamen non tres omnipotentes, sed unus omnipotens. Ita Deus Pater, Deus Filius, Deus [et] Spiritus Sanctus. Et tamen non tres dii, sed unus est Deus. Ita Dominus Pater, Dominus Filius, Dominus [et] Spiritus Sanctus. Et tamen non tres Domini, sed unus [est] Dominus. Quia, sicut singillatim unamquamque personam Deum ac Dominum confiteri christiana veritate compellimur: Ita tres Deos aut [tres] Dominos dicere Catholica religione prohibemur. Pater a nullo est factus: nec creatus, nec genitus. Filius a Patre solo est: non factus, nec creatus, sed genitus. Spiritus Sanctus a Patre et Filio: non factus, nec creatus, nec genitus, sed procedens. Unus ergo Pater, non tres Patres: unus Filius, non tres Filii: unus Spiritus Sanctus, non tres Spiritus Sancti. Et in hac Trinitate nihil prius aut posterius, nihil maius aut minus: Sed totae tres personae coaeternae sibi sunt et coaequales. Ita, ut per omnia, sicut iam supra dictum est, et unitas in Trinitate, et Trinitas in unitate veneranda sit. Qui vult ergo salvus esse, ita de Trinitate sentiat.

Sed necessarium est ad aeternam salutem, ut incarnationem quoque Domini nostri Iesu Christi fideliter credat. Est ergo fides recta ut credamus et confiteamur, quia Dominus noster Iesus Christus, Dei Filius, Deus [pariter] et homo est. Deus [est] ex substantia Patris ante saecula genitus: et homo est ex substantia matris in saeculo natus. Perfectus Deus, perfectus homo: ex anima rationali et humana carne subsistens. Aequalis Patri secundum divinitatem: minor Patre secundum humanitatem. Qui licet Deus sit et homo, non duo tamen, sed unus est Christus. Unus autem non conversione divinitatis in carnem, sed assumptione humanitatis in Deum. Unus omnino, non confusione substantiae, sed unitate personae. Nam sicut anima rationalis et caro unus est homo: ita Deus et homo unus est Christus. Qui passus est pro salute nostra: descendit ad inferos: tertia die resurrexit a mortuis. Ascendit ad [in] caelos, sedet ad dexteram [Dei] Patris [omnipotentis]. Inde venturus [est] judicare vivos et mortuos. Ad cujus adventum omnes homines resurgere habent cum corporibus suis; Et reddituri sunt de factis propriis rationem. Et qui bona egerunt, ibunt in vitam aeternam: qui vero mala, in ignem aeternum. Haec est fides Catholica, quam nisi quisque fideliter firmiterque crediderit, salvus esse non poterit.

Whosoever will be saved, before all things it is necessary that he hold the catholic faith. Which faith unless every one do keep whole and undefiled, without doubt he shall perish everlastingly. And the catholic faith is this: that we worship one God in Trinity, and Trinity in Unity; neither confounding the Persons, nor dividing the Essence. For there is one Person of the Father; another of the Son; and another of the Holy Ghost. But the Godhead of the Father, of the Son, and of the Holy Ghost, is all one; the Glory equal, the Majesty coeternal. Such as the Father is; such is the Son; and such is the Holy Ghost. The Father uncreated; the Son uncreated; and the Holy Ghost uncreated. The Father infinite; the Son infinite; and the Holy Ghost infinite. The Father eternal; the Son eternal; and the Holy Ghost eternal. And yet they are not three eternals; but one eternal. As also there are not three uncreated; nor three infinites, but one uncreated; and one infinite. So likewise the Father is Almighty; the Son Almighty; and the Holy Ghost Almighty. And yet they are not three Almighties; but one Almighty. So the Father is God; the Son is God; and the Holy Ghost is God. And yet they are not three Gods; but one God. So likewise the Father is Lord; the Son Lord; and the Holy Ghost Lord. And yet not three Lords; but one Lord. For like as we are compelled by the Christian verity; to acknowledge every Person by himself to be God and Lord; So are we forbidden by the catholic religion; to say, There are three Gods, or three Lords. The Father is made of none; neither created, nor begotten. The Son is of the Father alone; not made, nor created; but begotten. The Holy Ghost is of the Father and of the Son; neither made, nor created, nor begotten; but proceeding. So there is one Father, not three Fathers; one Son, not three Sons; one Holy Ghost, not three Holy Ghosts. And in this Trinity none is before, or after another; none is greater, or less than another. But the whole three Persons are coeternal, and coequal. So that in all things, as aforesaid; the Unity in Trinity, and the Trinity in Unity, is to be worshipped. He therefore that will be saved, let him thus think of the Trinity.
Furthermore, it is necessary to everlasting salvation; that he also believe faithfully the Incarnation of our Lord Jesus Christ. For the right Faith is, that we believe and confess; that our Lord Jesus Christ, the Son of God, is God and Man; God, of the Substance [Essence] of the Father; begotten before the worlds; and Man, of the Substance [Essence] of his mother, born in the world. Perfect God; and perfect Man, of a reasonable soul and human flesh subsisting. Equal to the Father, as touching his Godhead; and inferior to the Father as touching his Manhood. Who although he is God and Man; yet he is not two, but one Christ. One; not by conversion of the Godhead into flesh; but by assumption of the Manhood into God. One altogether; not by confusion of Substance [Essence]; but by unity of Person. For as the reasonable soul and flesh is one man; so God and Man is one Christ; Who suffered for our salvation; descended into hell; rose again the third day from the dead. He ascended into heaven, he sitteth on the right hand of God the Father Almighty, from whence he will come to judge the living and the dead. At whose coming all men will rise again with their bodies; And shall give account for their own works. And they that have done good shall go into life everlasting; and they that have done evil, into everlasting fire. This is the catholic faith; which except a man believe truly and firmly, he cannot be saved.

Today is also my favorite secular holiday, Father’s Day! I offer my deepest prayers for all fathers, spiritual, blood and adoptive, who show the paternity of God the Father to the world and sacrifice themselves in love for their families, especially for my own father who has been my best friend all my life. God bless you!

Missio Dei

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