The Holy Trinity

The Trinity is the term employed to signify the central doctrine of the Christian religion -that within the Godhead there are Three Persons, Father, Son, and Holy Spirit, each distinct one from another.  The word “Trinity” is not found in Scripture, but was first used by Theophilus of Antioch in 180 A.D.  Although the term is not explicitly defined in Scripture, the theology is explicitly stated in Matt. 28:19 when Jesus bids them to go and teach all nations, “baptizing them in the name of the Father, and of the Son, and of the Holy Ghost”.  There are also implicit references to the Trinity in the Old Testament, such as Gen. 1:26, which reads, “Let us make man in our image, according to our likeness.”

Early Christians upheld the idea of the Trinity and were quick to defend against heresies. In the third century, Sabellius, a Libyan priest, claimed there is only one person in the Godhead and that the Father, Son, and Holy Spirit were all one person with different “modes”.  Because Modalism asserts that there is only one person in the Godhead, passages that show Jesus talking to his Father (e.g., John 17), or declaring he is going to be with the Father (John 14:12, 28; 16:10) or saying that the two of them will send the Holy Spirit while they remain in heaven (John 14:16-17, 26; 15:26, 16:13–15; Acts 2:32–33) no longer make any logical sense.  Through a series of Church Councils over the following centuries, the doctrine of the Trinity was gradually defined and refined so that heresies such as Modalism, Arianism, Nestorianism, Monophysitism, and Monothelitism eventually died out.  Here are lists of the early Church Councils and the heresies that lead to them.

Of important note, however, Modalism has recently resurfaced in the twentieth century with the Oneness Pentecostal movement (referred to as Jesus Only theology).  It claims that Jesus is the only person in the Godhead and that the Father, Son, and Holy Spirit are “modes” or roles of Jesus.  This is in contrast to Scripture which clearly depicts the Holy Spirit as a person.  In Acts 13:2, the Holy Spirit says, “Set Barnabas and Saul apart for me for the work to which I have called them” and John 16 refers to the Holy Spirit as a “he” ten times. Scripture also says that the Holy Spirit can speak (Acts 8:29; 10:19, 20; 13:2), hear (John 16:13–15), teach (John 14:26), love (Rom. 15:30), and be blasphemed (Mark 3:29). Because the definition of a person is a rational being, these verses disprove any argument claiming that because the Holy Spirit is a spirit, then he is not a person. God, Satan, and the angels are all spirits and all of these are persons.

The Historical Development of the Doctrine:

Bible Verses:

Matthew 28:19


2 Cor. 13:14


Heb. 9:14


Church Father Quotes:

The Didache

“After the foregoing instructions, baptize in the name of the Father, and of the Son, and of the Holy Spirit, in living [running] water. . . . If you have neither, pour water three times on the head, in the name of the Father, and of the Son, and of the Holy Spirit” (Didache 7:1 [A.D. 70]).

Ignatius of Antioch

“[T]o the Church at Ephesus in Asia . . . chosen through true suffering by the will of the Father in Jesus Christ our God” (Letter to the Ephesians 1 [A.D. 110]).

“For our God, Jesus Christ, was conceived by Mary in accord with God’s plan: of the seed of David, it is true, but also of the Holy Spirit” (ibid., 18:2).

Justin Martyr

“We will prove that we worship him reasonably; for we have learned that he is the Son of the true God himself, that he holds a second place, and the Spirit of prophecy a third. For this they accuse us of madness, saying that we attribute to a crucified man a place second to the unchangeable and eternal God, the Creator of all things; but they are ignorant of the mystery which lies therein” (First Apology 13:5–6 [A.D. 151]).

Theophilus of Antioch

“It is the attribute of God, of the most high and almighty and of the living God, not only to be everywhere, but also to see and hear all; for he can in no way be contained in a place. . . . The three days before the luminaries were created are types of the Trinity: God, his Word, and his Wisdom” (To Autolycus 2:15 [A.D. 181]).

Irenaeus of Lyons 

“For the Church, although dispersed throughout the whole world even to the ends of the earth, has received from the apostles and from their disciples the faith in one God, the Father Almighty . . . and in one Jesus Christ, the Son of God, who became flesh for our salvation; and in the Holy Spirit” (Against Heresies 1:10:1 [A.D. 189]).

Tertullian of Carthage 

“We do indeed believe that there is only one God, but we believe that under this dispensation, or, as we say, oikonomia, there is also a Son of this one only God, his Word, who proceeded from him and through whom all things were made and without whom nothing was made. . . . We believe he was sent down by the Father, in accord with his own promise, the Holy Spirit, the Paraclete, the sanctifier of the faith of those who believe in the Father and the Son, and in the Holy Spirit” (Against Praxeas 2 [A.D. 216]).

“And at the same time the mystery of the oikonomia is safeguarded, for the unity is distributed in a Trinity. Placed in order, the three are the Father, Son, and Spirit. They are three, however, not in condition, but in degree; not in being, but in form; not in power, but in kind; of one being, however, and one condition and one power, because he is one God of whom degrees and forms and kinds are taken into account in the name of the Father, and of the Son, and of the Holy Spirit” (ibid.).

“Keep always in mind the rule of faith which I profess and by which I bear witness that the Father and the Son and the Spirit are inseparable from each other, and then you will understand what is meant by it. Observe now that I say the Father is other [distinct], the Son is other, and the Spirit is other. This statement is wrongly understood by every uneducated or perversely disposed individual, as if it meant diversity and implied by that diversity a separation of Father, Son, and Holy Spirit” (ibid., 9).

“Thus the connection of the Father in the Son, and of the Son in the Paraclete, produces three coherent persons, who are yet distinct one from another. These three are, one essence, not one person, as it is said, ‘I and my Father are one’ [John 10:30], in respect of unity of being not singularity of number” (ibid., 25).

Origen of Alexandria 

“For we do not hold that which the heretics imagine: that some part of the being of God was converted into the Son, or that the Son was procreated by the Father from non-existent substances, that is, from a being outside himself, so that there was a time when he [the Son] did not exist” (The Fundamental Doctrines 4:4:1 [A.D. 225]).

“For it is the Trinity alone which exceeds every sense in which not only temporal but even eternal may be understood. It is all other things, indeed, which are outside the Trinity, which are to be measured by time and ages” (ibid.).

Hippolytus of Rome 

“The Word alone of this God is from God himself, wherefore also the Word is God, being the being of God” (Refutation of All Heresies 10:29 [A.D. 228]).

Pope Dionysius

“Next, then, I may properly turn to those who divide and cut apart and destroy the most sacred proclamation of the Church of God, making of it [the Trinity], as it were, three powers, distinct substances, and three godheads. . . . [Some heretics] proclaim that there are in some way three gods, when they divide the sacred unity into three substances foreign to each other and completely separate” (Letter to Dionysius of Alexandria 1 [A.D. 262]).

“Therefore, the divine Trinity must be gathered up and brought together in one, a summit, as it were, I mean the omnipotent God of the universe. . . . It is blasphemy, then, and not a common one but the worst, to say that the Son is in any way a handiwork [creature]. . . . But if the Son came into being [was created], there was a time when these attributes did not exist; and, consequently, there was a time when God was without them, which is utterly absurd” (ibid., 1–2).

“Neither, then, may we divide into three godheads the wonderful and divine unity. . . . Rather, we must believe in God, the Father Almighty; and in Christ Jesus, his Son; and in the Holy Spirit; and that the Word is united to the God of the universe. ‘For,’ he says, ‘The Father and I are one,’ and ‘I am in the Father, and the Father in me’” (ibid., 3).

Gregory the Wonderworker

“There is one God. . . . There is a perfect Trinity, in glory and eternity and sovereignty, neither divided nor estranged. Wherefore there is nothing either created or in servitude in the Trinity; nor anything superinduced, as if at some former period it was non-existent, and at some later period it was introduced. And thus neither was the Son ever wanting to the Father, nor the Spirit to the Son; but without variation and without change, the same Trinity abides ever” (Declaration of Faith [A.D. 265]).

Sechnall of Ireland

“Hymns, with Revelation and the Psalms of God [Patrick] sings, and does expound the same for the edifying of God’s people. This law he holds in the Trinity of the sacred Name and teaches one being in three persons” (Hymn in Praise of St. Patrick 22 [A.D. 444]).

Patrick of Ireland

“I bind to myself today the strong power of an invocation of the Trinity—the faith of the Trinity in unity, the Creator of the universe” (The Breastplate of St. Patrick 1 [A.D. 447]).

“[T]here is no other God, nor has there been heretofore, nor will there be hereafter, except God the Father unbegotten, without beginning, from whom is all beginning, upholding all things, as we say, and his Son Jesus Christ, whom we likewise to confess to have always been with the Father—before the world’s beginning. . . . Jesus Christ is the Lord and God in whom we believe . . . and who has poured out on us abundantly the Holy Spirit . . . whom we confess and adore as one God in the Trinity of the sacred Name” (Confession of St. Patrick 4 [A.D. 452]).

Augustine of Hippo 

“All the Catholic interpreters of the divine books of the Old and New Testaments whom I have been able to read, who wrote before me about the Trinity, which is God, intended to teach in accord with the Scriptures that the Father and the Son and the Holy Spirit are of one and the same substance constituting a divine unity with an inseparable equality; and therefore there are not three gods but one God, although the Father begot the Son, and therefore he who is the Son is not the Father; and the Holy Spirit is neither the Father nor the Son but only the Spirit of the Father and of the Son, himself, too, coequal to the Father and to the Son and belonging to the unity of the Trinity” (The Trinity1:4:7 [A.D. 408]).

Fulgence of Ruspe

“See, in short you have it that the Father is one, the Son another, and the Holy Spirit another; in Person, each is other, but in nature they are not other. In this regard he says: ‘The Father and I, we are one’ (John 10:30). He teaches us that onerefers to their nature, and we are to their Persons. In like manner it is said: ‘There are three who bear witness in heaven, the Father, the Word, and the Spirit; and these three are one’ (1 John 5:7)” (The Trinity 4:1–2 [c. A.D. 515]).

“But in the one true God and Trinity it is naturally true not only that God is one but also that he is a Trinity, for the reason that the true God himself is a Trinity of Persons and one in nature. Through this natural unity the whole Father is in the Son and in the Holy Spirit, and the whole Holy Spirit, too, is in the Father and in the Son. None of these is outside any of the others; because no one of them precedes any other of them in eternity or exceeds any other in greatness, or is superior to any other in power” (The Rule of Faith 4 [c. A.D. 523).

The Letter of Barnabas

“And further, my brethren, if the Lord [Jesus] endured to suffer for our soul, he being the Lord of all the world, to whom God said at the foundation of the world, ‘Let us make man after our image, and after our likeness,’ understand how it was that he endured to suffer at the hand of men” (Letter of Barnabas 5 [A.D. 74], emphasis added).

Ignatius of Antioch

“Jesus Christ . . . was with the Father before the beginning of time, and in the end was revealed. . . . Jesus Christ . . . came forth from one Father and is with and has gone to one [Father]. . . . [T]here is one God, who has manifested himself by Jesus Christ his Son, who is his eternal Word, not proceeding forth from silence, and who in all things pleased him that sent him” (Letter to the Magnesians 6–8 [A.D. 110], emphasis added).

Justin Martyr

“God speaks in the creation of man with the very same design, in the following words: ‘Let us make man after our image and likeness.’ . . . I shall quote again the words narrated by Moses himself, from which we can indisputably learn that [God] conversed with someone numerically distinct from himself and also a rational being. . . . But this offspring who was truly brought forth from the Father, was with the Father before all the creatures, and the Father communed with him” (Dialogue with Trypho the Jew 62 [A.D. 155]).


“[The Father] sent the Word that he might be manifested to the world. . . . This is he who was from the beginning, who appeared as if new, and was found old. . . . This is he who, being from everlasting, is today called the Son” (Letter to Diognetus 11 [A.D. 160], emphasis added).


“It was not angels, therefore, who made us nor who formed us, neither had angels power to make an image of God, nor anyone else. . . . For God did not stand in need of these in order to accomplish what he had himself determined with himself beforehand should be done, as if he did not possess his own hands. For with him [the Father] were always present the Word and Wisdom, the Son and the Spirit, by whom and in whom, freely and spontaneously, he made all things, to whom also he speaks, saying, ‘Let us make man in our image and likeness’ [Gen. 1:26]” (Against Heresies 4:20:1 [A.D. 189], emphasis added).


“While keeping to this demurrer always, there must, nevertheless, be place for reviewing for the sake of the instruction and protection of various persons. . . . This is especially so in the case of the present heresy [Sabellianism], which considers itself to have the pure truth when it supposes that one cannot believe in the one only God in any way other than by saying that Father, Son, and Spirit are the selfsame person. As if one were not all . . . through the unity of substance” (Against Praxeas 2:3–4 [A.D. 216]).

“Keep always in mind the rule of faith which I profess and by which I bear witness that the Father and the Son and the Spirit are inseparable from each other, and then you will understand what is meant by it. Observe, now, that I say the Father is other [distinct], and the Son is other, and the Spirit is other. . . . I say this, however, out of necessity, since they contend that the Father and the Son and the Spirit are the selfsame person” (ibid. 9:1).

Pope Dionysius

“Next, then, I may properly turn to those who divide and cut apart and destroy the monarchy, the most sacred proclamation of the Church of God, making of it, as it were, three powers, distinct substances, and three godheads. I have heard that some of your catechists and teachers of the divine Word take the lead in this tenet. They are, so to speak, diametrically opposed to the opinion of Sabellius. He, in his blasphemy, says that the Son is the Father and vice versa” (Letters of Pope Dionysius to Bishop Dionysius of Alexandria 1:1 [A.D. 262]).

Gregory the Wonderworker

“But some treat the Holy Trinity in an awful manner, when they confidently assert that there are not three persons, and introduce (the idea of) a person devoid of subsistence. Wherefore we clear ourselves of Sabellius, who says that the Father and the Son are the same [person]. . . . We forswear this, because we believe that three persons—namely, Father, Son, and Holy Spirit—are declared to possess the one Godhead: for the one divinity showing itself forth according to nature in the Trinity establishes the oneness of the nature” (A Sectional Confession of Faith 8 [A.D. 262]).

“But if they say, ‘How can there be three persons, and how but one divinity?’ we shall make this reply: That there are indeed three persons, inasmuch as there is one person of God the Father, and one of the Lord the Son, and one of the Holy Spirit; and yet that there is but one divinity, inasmuch as . . . there is one substance in the Trinity” (ibid., 14).


“For the kingdom of the Father, of the Son, and of the Holy Ghost, is one, even as their substance is one and their dominion one. Whence also, with one and the same adoration, we worship the one deity in three persons, subsisting without beginning, uncreated, without end, and to which there is no successor. For neither will the Father ever cease to be the Father, nor again the Son to be the Son and King, nor the Holy Ghost to be what in substance and personality he is. For nothing of the Trinity will suffer diminution, either in respect of eternity, or of communion, or of sovereignty” (Oration on the Psalms 5 [A.D. 305]).


“[The Trinity] is a Trinity not merely in name or in a figurative manner of speaking; rather, it is a Trinity in truth and in actual existence. Just as the Father is he that is, so also his Word is one that is and is God over all. And neither is the Holy Spirit nonexistent but actually exists and has true being” (Letters to Serapion 1:28 [A.D. 359]).

“They [the Father and the Son] are one, not as one thing now divided into two, but really constituting only one, nor as one thing twice named, so that the same becomes at one time the Father and at another his own Son. This latter is what Sabellius held, and he was judged a heretic. On the contrary, they are two, because the Father is Father and is not his own Son, and the Son is Son and not his own Father” (Discourses Against the Arians 3:4 [A.D. 360]).

Non-Catholic Quotes:


“[W]ho does not acknowledge that the person of the Son is second after the Father, when he reads that it was said by the Father, consequently to the Son, ‘Let us make man in our image and our likeness’ [Gen. 1:26]? Or when he reads [as having been said] to Christ: ‘Thou art my Son, this day have I begotten you. Ask of me, and I will give you the heathens for your inheritance, and the ends of the earth for your possession’ [Ps. 2:7–8]? Or when also that beloved writer says: ‘The Lord said unto my Lord, Sit thou on my right hand, until I shall make your enemies the stool of your feet’ [Ps. 110:1]? Or when, unfolding the prophecies of Isaiah, he finds it written thus: ‘Thus says the Lord to Christ my Lord’? Or when he reads: ‘I came not down from heaven to do mine own will, but the will of him that sent me’ [John 6:38]? Or when he finds it written: ‘Because he who sent me is greater than I’ [cf. John 14:24, 28]? Or when he finds it placed side by side with others: ‘Moreover, in your law it is written that the witness of two is true. I bear witness of myself, and the Father who sent me bears witness of me’ [cf. John 8:17–18]?” (Treatise on the Trinity 26 [A.D. 235]).