Unitarianism is a catch-all term for those who reject the Deity of Christ, yet affirm Monotheistic Christianity. They believe that Jesus was the Savior, and an exalted creation, but not God. They also reject the distinct personage of the Holy Spirit.
Because the Scriptural proof for the Deity of Christ is so voluminous, this article will follow a reference list format, with brief explanations below each item.
Unitarians often pseudohistorically claim that the Deity of Christ is an invention by the Catholic Church, circa the fourth century. What follows are some quotations from early Christian writers, which attest to the Deity of Christ, contrary to such claims.
These are not cited to establish the doctrine of Christ's divinity. That can only be done with Scripture, as above. However, these citations demonstrate belief in the doctrine by Christians who lived prior to the foundation of the Catholic Church:
Ignatius to the Ephesians (108-140 AD) - Greeting
Ignatius, who is also called Theophorus, to the Church which is at Ephesus, in Asia, deservedly most happy, being blessed in the greatness and fullness of God the Father, and predestinated before the ages of time, that it should be always for an enduring and unchangeable glory, being united and elected through the true passion by the will of the Father, and Jesus Christ, our God: Abundant happiness through Jesus Christ, and His undefiled grace.
Ignatius - Epistle to the Ephesians (108-140 AD)
7 There is one Physician who is possessed both of flesh and spirit; both made and not made; God existing in flesh; true life in death; both of Mary and of God; first passible and then impassible — even Jesus Christ our Lord.
Ignatius - Epistle to the Ephesians (108-140 AD)
18 Let my spirit be counted as nothing for the sake of the cross, which is a stumbling-block to those that do not believe, but to us salvation and life eternal. Where is the wise man? Where the disputer? Where is the boasting of those who are styled prudent? For our God, Jesus Christ, was, according to the appointment of God, conceived in the womb by Mary, of the seed of David, but by the Holy Ghost. He was born and baptized, that by His passion He might purify the water.
Ignatius - Epistle to the Ephesians (108-140 AD)
19 Hence every kind of magic was destroyed, and every bond of wickedness disappeared; ignorance was removed, and the old kingdom abolished, God Himself being manifested in human form for the renewal of eternal life. And now that took a beginning which had been prepared by God. Henceforth all things were in a state of tumult, because He meditated the abolition of death.
Ignatius - Epistle to the Romans (108-140 AD)
3 Nothing visible is eternal. For the things which are seen are temporal, but the things which are not seen are eternal. For our God, Jesus Christ, now that He is with the Father, is all the more revealed in His glory. Christianity is not a thing of silence only, but also of manifest greatness.
Ignatius - Epistle to the Smyrnaeans (108-140 AD)
1 I glorify God, even Jesus Christ, who has given you such wisdom.
Ignatius - Epistle to the Polycarp (108-140 AD)
3 Be ever becoming more zealous than what you are. Weigh carefully the times. Look for Him who is above all time, eternal and invisible, yet who became visible for our sakes; impalpable and impassible, yet who became passible on our account; and who in every kind of way suffered for our sakes.
Justin Martyr - Dialogue with Trypho (165 AD)
36 As you wish, Trypho, I shall come to these proofs which you seek in the fitting place; but now you will permit me first to recount the prophecies, which I wish to do in order to prove that Christ is called both God and Lord of hosts, and Jacob, in parable by the Holy Spirit;
Justin Martyr - Dialogue with Trypho (165 AD)
63 Hearken, O daughter, and behold, and incline your ear, and forget your people and the house of your father; and the King shall desire your beauty: because he is your Lord, and you shall worship Him.' Therefore these words testify explicitly that He is witnessed to by Him who established these things, as deserving to be worshipped, as God and as Christ.
Justin Martyr - Dialogue with Trypho (165 AD)
126 For if you had understood what has been written by the prophets, you would not have denied that He was God, Son of the only, unbegotten, unutterable God.
Justin Martyr - Dialogue with Trypho (165 AD)
128 And that Christ being Lord, and God the Son of God, and appearing formerly in power as Man, and Angel, and in the glory of fire as at the bush, so also was manifested at the judgment executed on Sodom, has been demonstrated fully by what has been said.
Justin Martyr - First Apology (165 AD)
63 For they who affirm that the Son is the Father, are proved neither to have become acquainted with the Father, nor to know that the Father of the universe has a Son; who also, being the first-begotten Word of God, is even God.
Melito of Sardis - Homily on Passover (180 AD)
8 For the one who was born as Son, and led to slaughter as a lamb, and sacrificed as a sheep, and buried as a man, rose up from the dead as God, since he is by nature both God and man.
95 And thus he was lifted up upon the tree, and an inscription was affixed identifying the one who had been murdered. Who was he? It is painful to tell, but it is more dreadful not to tell. Therefore, hear and tremble because of him for whom the earth trembled.
96 The one who hung the earth in space, is himself hanged; the one who fixed the heavens in place, is himself impaled; the one who firmly fixed all things, is himself firmly fixed to the tree. The Lord is insulted, God has been murdered, the King of Israel has been destroyed by the right hand of Israel.
97 O frightful murder! O unheard of injustice! The Lord is disfigured and he is not deemed worthy of a cloak for his naked body, so that he might not be seen exposed. For this reason the stars turned and fled, and the day grew quite dark, in order to hide the naked person hanging on the tree, darkening not the body of the Lord, but the eyes of men.
104 This is the one who made the heavens and the earth, and who in the beginning created man, who was proclaimed through the law and prophets, who became human via the virgin, who was hanged upon a tree, who was buried in the earth, who was resurrected from the dead, and who ascended to the heights of heaven, who sits at the right hand of the Father, who has authority to judge and to save everything, through whom the Father created everything from the beginning of the world to the end of the age.
Irenaeus - Against Heresies (200 AD) - Book 1, Chapter 10
1 In order that to Christ Jesus, our Lord, and God, and Saviour, and King, according to the will of the invisible Father, every knee should bow, of things in heaven, and things in earth, and things under the earth, and that every tongue should confess Philippians 2:10-11 to Him, and that He should execute just judgment towards all;
Irenaeus - Against Heresies (200 AD) - Book 3, Chapter 19
2 For I have shown from the Scriptures, that no one of the sons of Adam is as to everything, and absolutely, called God, or named Lord. But that He is Himself in His own right, beyond all men who ever lived, God, and Lord, and King Eternal, and the Incarnate Word, proclaimed by all the prophets, the apostles, and by the Spirit Himself, may be seen by all who have attained to even a small portion of the truth.
Irenaeus - Against Heresies (200 AD) - Book 3, Chapter 21
4 Carefully, then, has the Holy Ghost pointed out, by what has been said, His birth from a virgin, and His essence, that He is God (for the name Emmanuel indicates this).
Irenaeus - Against Heresies (200 AD) - Book 4, Chapter 5
2 Christ Himself, therefore, together with the Father, is the God of the living, who spoke to Moses, and who was also manifested to the fathers.
Irenaeus - Against Heresies (200 AD) - Book 4, Chapter 6
7 He, therefore, who was known, was not a different being from Him who declared No man knows the Father, but one and the same, the Father making all things subject to Him; while He received testimony from all that He was very man, and that He was very God, from the Father, from the Spirit, from angels, from the creation itself, from men, from apostate spirits and demons, from the enemy, and last of all, from death itself.
Clement of Alexandria - Exhortation to the Heathen (215 AD)
1 This Word, then, the Christ, the cause of both our being at first (for He was in God) and of our well-being, this very Word has now appeared as man, He alone being both, both God and man - the Author of all blessings to us; by whom we, being taught to live well, are sent on our way to life eternal.
The Word, who in the beginning bestowed on us life as Creator when He formed us, taught us to live well when He appeared as our Teacher; that as God He might afterwards conduct us to the life which never ends.
Clement of Alexandria - Exhortation to the Heathen (215 AD)
10 For it was not without divine care that so great a work was accomplished in so brief a space by the Lord, who, though despised as to appearance, was in reality adored, the expiator of sin, the Saviour, the clement, the Divine Word, He that is truly most manifest Deity, He that is made equal to the Lord of the universe; because He was His Son, and the Word was in God, not disbelieved in by all when He was first preached, nor altogether unknown when, assuming the character of man, and fashioning Himself in flesh, He enacted the drama of human salvation: for He was a true champion and a fellow-champion with the creature.
Hippolytus - Refutation of All Heresies (235 AD) - Book 10
29 The Logos alone of this God is from God himself; wherefore also the Logos is God, being the substance of God.
Hippolytus - Fragments from the Scriptural Commentaries (235 AD) - Luke
23 For this reason the warders of Hades trembled when they saw Him; and the gates of brass and the bolts of iron were broken. For, lo, the Only-begotten entered, a soul among souls, God the Word with a (human) soul. For His body lay in the tomb, not emptied of divinity; but as, while in Hades, He was in essential being with His Father, so was He also in the body and in Hades. For the Son is not contained in space, just as the Father; and He comprehends all things in Himself. But of His own will he dwelt in a body animated by a soul, in order that with His soul He might enter Hades, and not with His pure divinity.
Hippolytus - Against Plato (235 AD)
3 For all, the righteous and the unrighteous alike, shall be brought before God the Word. For the Father has committed all judgment to Him; and in fulfilment of the Father's counsel, He comes as Judge whom we call Christ.
Hippolytus - Against Noetus (235 AD)
17 Let us believe then, dear brethren, according to the tradition of the apostles, that God the Word came down from heaven, (and entered) into the holy Virgin Mary, in order that, taking the flesh from her, and assuming also a human, by which I mean a rational soul, and becoming thus all that man is with the exception of sin, He might save fallen man, and confer immortality on men who believe in His name. In all, therefore, the word of truth is demonstrated to us, to wit, that the Father is One, whose word is present (with Him), by whom He made all things; whom also, as we have said above, the Father sent forth in later times for the salvation of men.
This (Word) was preached by the law and the prophets as destined to come into the world. And even as He was preached then, in the same manner also did He come and manifest Himself, being by the Virgin and the Holy Spirit made a new man; for in that He had the heavenly (nature) of the Father, as the Word and the earthly (nature), as taking to Himself the flesh from the old Adam by the medium of the Virgin, He now, coming forth into the world, was manifested as God in a body, coming forth too as a perfect man. For it was not in mere appearance or by conversion, but in truth, that He became man.
18 Thus then, too, though demonstrated as God, He does not refuse the conditions proper to Him as man, since He hungers and toils and thirsts in weariness, and flees in fear, and prays in trouble. And He who as God has a sleepless nature, slumbers on a pillow.
Tertullian - Treatise on the Soul (240 AD)
41 For God alone is without sin; and the only man without sin is Christ, since Christ is also God.
Tertullian - Apology (240 AD)
21 Thus Christ is Spirit of Spirit, and God of God, as light of light is kindled. The material matrix remains entire and unimpaired, though you derive from it any number of shoots possessed of its qualities; so, too, that which has come forth out of God is at once God and the Son of God, and the two are one. In this way also, as He is Spirit of Spirit and God of God, He is made a second in manner of existence - in position, not in nature; and He did not withdraw from the original source, but went forth. This ray of God, then, as it was always foretold in ancient times, descending into a certain virgin, and made flesh in her womb, is in His birth God and man united.
Tertullian - Against Praxeas (240 AD)
2 As if in this way also one were not All, in that All are of One, by unity (that is) of substance; while the mystery of the dispensation is still guarded, which distributes the Unity into a Trinity, placing in their order the three Persons - the Father, the Son, and the Holy Ghost: three, however, not in condition, but in degree; not in substance, but in form; not in power, but in aspect; yet of one substance, and of one condition, and of one power, inasmuch as He is one God, from whom these degrees and forms and aspects are reckoned, under the name of the Father, and of the Son, and of the Holy Ghost. How they are susceptible of number without division, will be shown as our treatise proceeds.
Origen - De Principiis (254 AD) - Preface
4 Secondly, That Jesus Christ Himself, who came (into the world), was born of the Father before all creatures; that, after He had been the servant of the Father in the creation of all things — For by Him were all things made — He in the last times, divesting Himself (of His glory), became a man, and was incarnate although God, and while made a man remained the God which He was;
Origen - De Principiis (254 AD) - Book 1, Chapter 2
2 Wherefore we have always held that God is the Father of His only-begotten Son, who was born indeed of Him, and derives from Him what He is, but without any beginning, not only such as may be measured by any divisions of time, but even that which the mind alone can contemplate within itself, or behold, so to speak, with the naked powers of the understanding.
Origen - De Principiis (254 AD) - Book 1, Chapter 2
4 But it is monstrous and unlawful to compare God the Father, in the generation of His only-begotten Son, and in the substance of the same, to any man or other living thing engaged in such an act; for we must of necessity hold that there is something exceptional and worthy of God which does not admit of any comparison at all, not merely in things, but which cannot even be conceived by thought or discovered by perception, so that a human mind should be able to apprehend how the unbegotten God is made the Father of the only-begotten Son. Because His generation is as eternal and everlasting as the brilliancy which is produced from the sun. For it is not by receiving the breath of life that He is made a Son, by any outward act, but by His own nature.
Origen - De Principiis (254 AD) - Book 1, Chapter 2
10 And that you may understand that the omnipotence of Father and Son is one and the same, as God and the Lord are one and the same with the Father, listen to the manner in which John speaks in the Apocalypse: Thus says the Lord God, which is, and which was, and which is to come, the Almighty. For who else was He which is to come than Christ? And as no one ought to be offended, seeing God is the Father, that the Saviour is also God; so also, since the Father is called omnipotent, no one ought to be offended that the Son of God is also called omnipotent.