Tertullian: Trinity is the Faith of the Ancient Church

Chapter 2. The Catholic Doctrine of the Trinity and Unity, Sometimes Called the Divine Economy, or Dispensation of the Personal Relations of the Godhead

In the course of time, then, the Father forsooth was born, and the Father suffered, God Himself, the Lord Almighty, whom in their preaching they declare to be Jesus Christ.

We, however, as we indeed always have done (and more especially since we have been better instructed by the Paraclete, who leads men indeed into all truth), believe that there is one only God, but under the following dispensation, or οἰκονομία, as it is called, that this one only God has also a Son, His Word, who proceeded from Himself, by whom all things were made, and without whom nothing was made.

Him we believe to have been sent by the Father into the Virgin, and to have been born of her — being both Man and God, the Son of Man and the Son of God, and to have been called by the name of Jesus Christ; we believe Him to have suffered, died, and been buried, according to the Scriptures, and, after He had been raised again by the Father and taken back to heaven, to be sitting at the right hand of the Father, and that He will come to judge the quick and the dead; who sent also from heaven from the Father, according to His own promise, the Holy Ghost, the Paraclete, the sanctifier of the faith of those who believe in the Father, and in the Son, and in the Holy Ghost.

That this rule of faith HAS COME DOWN TO US FROM THE BEGINNING OF THE GOSPEL, EVEN BEFORE ANY OF THE OLDER HERETICS, MUCH BEFORE PRAXEAS, a pretender of yesterday, will be apparent both from the lateness of date which marks all heresies, and also from the absolutely novel character of our new-fangled Praxeas.

In this principle also we must henceforth find a presumption of equal force against all heresies whatsoever — that whatever is first is true, whereas that is spurious which is later in date.

But keeping this prescriptive rule inviolate, still some opportunity must be given for reviewing (the statements of heretics), with a view to the instruction and protection of various persons; were it only that it may not seem that each perversion of the truth is condemned without examination, and simply prejudged; especially in the case of this heresy, which supposes itself to possess the pure truth, in thinking that one cannot believe in One Only God in any other way than by saying that the Father, the Son, and the Holy Ghost are the very selfsame Person.

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.

(Against Praxeas; emphasis mine)

Chapter 22. Sundry Passages of St. John Quoted, to Show the Distinction Between the Father and the Son. Even Praxeas’ Classic Text — I and My Father are One — Shown to Be Against Him

Again, whose doctrine does He announce, at which all were astonished? Was it His own or the Father’s? So, when they were in doubt among themselves whether He were the Christ (not as being the Father, of course but as the Son), He says to them You are not ignorant whence I am; and I am not come of myself, but He that sent me is true, whom you know not; but I know Him, because I am from Him.

He did not say, Because I myself am He; and, I have sent my own self: but His words are, He has sent me.

When, likewise, the Pharisees sent men to apprehend Him, He says: Yet a little while am I with you, and (then) I go unto Him that sent me.

When, however, He declares that He is not alone, and uses these words, but I and the Father that sent me, John 8:16 does He not show that there are Two — Two, and yet inseparable?

Indeed, this was the sum and substance of what He was teaching them, that they were inseparably Two; since, after citing the law when it affirms the truth of two men’s testimony, He adds at once: I am one who am bearing witness of myself; and the Father (is another,) who has sent me, and bears witness of me. Now, if He were one — being at once both the Son and the Father — He certainly would not have quoted the sanction of the law, which requires not the testimony of one, but of two.

Likewise, when they asked Him where His Father was, He answered them, that they had known neither Himself nor the Father; and in this answer He plainly told them of Two, whom they were ignorant of.

Granted that if they had known Him, they would have known the Father also, this certainly does not imply that He was Himself both Father and Son; but that, by reason of the inseparability of the Two, it was impossible for one of them to be either acknowledged or unknown without the other.

He that sent me, says He, is true; and I am telling the world those things which I have heard of Him. John 8:26

And the Scripture narrative goes on to explain in an exoteric manner, that they understood not that He spoke to them concerning the Father, although they ought certainly to have known that the Father’s words were uttered in the Son, because they read in Jeremiah, And the Lord said to me, Behold, I have put my words in your mouth; Jeremiah 1:9 and again in Isaiah, The Lord has given to me the tongue of learning that I should understand when to speak a word in season. Isaiah 50:4

In accordance with which, Christ Himself says: Then shall you know that I am He and that I am saying nothing of my own self; but that, as my Father has taught me, so I speak, because He that sent me is with me. John 8:28-29 This also amounts to a proof that they were Two, (although) undivided.

Likewise, when upbraiding the Jews in His discussion with them, because they wished to kill Him, He said, I speak that which I have seen with my Father, and you do that which you have seen with your father; but now you seek to kill me, a man that has told you the truth which I have heard of God; and again, If God were your Father, you would love me, for I proceeded forth and came from God, (still they are not hereby separated, although He declares that He proceeded forth from the Father.

Some persons indeed seize the opportunity afforded them in these words to propound their heresy of His separation; but His coming out from God is like the ray’s procession from the sun, and the river’s from the fountain, and the tree’s from the seed); I have not a devil, but I honour my Father; again, If I honour myself, my honour is nothing: it is my Father that honours me, of whom you say, that He is your God: yet you have not known Him, but I know Him; and if I should say, I know Him not, I shall be a liar like you; but I know Him, and keep His saying. John 8:54-55

But when He goes on to say,  Your father Abraham rejoiced to see my day; and he saw it, and was glad, He certainly proves that it was not the Father that appeared to Abraham, but the Son.

In like manner He declares, in the case of the man born blind, that He must do the works of the Father which had sent Him; John 9:4 and after He had given the man sight, He said to him, Do you believe in the Son of God?

Then, upon the man’s inquiring who He was, He proceeded to reveal Himself to him, as that Son of God whom He had announced to him as the right object of his faith. In a later passage He declares that He is known by the Father, and the Father by Him; John 10:15 adding that He was so wholly loved by the Father, that He was laying down His life, because He had received this commandment from the Father.

When He was asked by the Jews if He were the very Christ (meaning, of course, the Christ of God; for to this day the Jews expect not the Father Himself, but the Christ of God, it being nowhere said that the Father will come as the Christ), He said to them, I am telling you, and yet you do not believe: the works which I am doing, in my Father’s name, they actually bear witness of me.

Witness of what? Of that very thing, to be sure, of which they were making inquiry — whether He were the Christ of God. Then, again, concerning His sheep, and (the assurance) that no man should pluck them out of His hand, He says, My Father, which gave them to me, is greater than all; adding immediately, I am and my Father are one.

Here, then, they take their stand, too infatuated, nay, too blind, to see in the first place that there is in this passage an intimation of Two Beings —  I and my Father; then that there is a plural predicate, are, inapplicable to one person only; and lastly, that (the predicate terminates in an abstract, not a personal noun)— we are one thing Unum, not one person Unus. For if He had said one Person, He might have rendered some assistance to their opinion. Unus, no doubt, indicates the singular number; but (here we have a case where) Two are still the subject in the masculine gender. He accordingly says Unum, a neuter term, which does not imply singularity of number, but unity of essence, likeness, conjunction, affection on the Father’s part, who loves the Son, and submission on the Son’s, who obeys the Father’s will.

When He says, I and my Father are one in essence— Unum— He shows that there are Two, whom He puts on an equality and unites in one.

He therefore adds to this very statement, that He had showed them many works from the Father, for none of which did He deserve to be stoned. John 10:32

And to prevent their thinking Him deserving of this fate, as if He had claimed to be considered as God Himself, that is, the Father, by having said, I and my Father are One, representing Himself as the Father’s divine Son, and not as God Himself, He says, If it is written in your law, I said, You are gods; and if the Scripture cannot be broken, say of Him whom the Father has sanctified and sent into the world, that He blasphemes, because He said, I am the Son of God? If I do not the works of my Father, believe me not; but if I do, even if you will not believe me, still believe the works; and know that I am in the Father, and the Father in me.

It must therefore be by the works that the Father is in the Son, and the Son in the Father; and so it is by the works that we understand that the Father is one with the Son.

All along did He therefore strenuously aim at this conclusion, that while they were of one power and essence, they should still be believed to be Two; for otherwise, unless they were believed to be Two, the Son could not possibly be believed to have any existence at all…

Chapter 25. The Paraclete, or Holy Ghost. He is Distinct from the Father and the Son as to Their Personal Existence. One and Inseparable from Them as to Their Divine Nature. Other Quotations Out of St. John’s Gospel

What follows Philip’s question, and the Lord’s whole treatment of it, to the end of John’s Gospel, continues to furnish us with statements of the same kind, distinguishing the Father and the Son, with the properties of each.

Then there is the Paraclete or Comforter, also, which He promises to pray for to the Father, and to send from heaven after He had ascended to the Father. He is called another Comforter, indeed; John 14:16 but in what way He is another we have already shown, He shall receive of mine, says Christ, John 16:14 just as Christ Himself received of the Father’s.

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 substance not singularity of number.

Run through the whole Gospel, and you will find that He whom you believe to be the Father (described as acting for the Father, although you, for your part, forsooth, suppose that the Father, being the husbandman, John 15:1 must surely have been on earth) is once more recognised by the Son as in heaven, when, lifting up His eyes thereto, John 17:1 He commended His disciples to the safe-keeping of the Father. John 17:11

We have, moreover, in that other Gospel a clear revelation, i.e. of the Son’s distinction from the Father, My God, why have You forsaken me? Matthew 27:46 and again, (in the third Gospel,) Father, into Your hands I commend my spirit. Luke 23:46

But even if (we had not these passages, we meet with satisfactory evidence) after His resurrection and glorious victory over death. Now that all the restraint of His humiliation is taken away, He might, if possible, have shown Himself as the Father to so faithful a woman (as Mary Magdalene) when she approached to touch Him, out of love, not from curiosity, nor with Thomas’ incredulity.

But not so; Jesus says unto her, Touch me not, for I am not yet ascended to my Father; but go to my brethren (and even in this He proves Himself to be the Son; for if He had been the Father, He would have called them His children, instead of His brethren), and say unto them, I ascend unto my Father and your Father, and to my God and your God. John 20:17

Now, does this mean, I ascend as the Father to the Father, and as God to God? Or as the Son to the Father, and as the Word to God? Wherefore also does this Gospel, at its very termination, intimate that these things were ever written, if it be not, to use its own words, that you might believe that Jesus Christ is the Son of God? John 20:31

Whenever, therefore, you take any of the statements of this Gospel, and apply them to demonstrate the identity of the Father and the Son, supposing that they serve your views therein, you are contending against the definite purpose of the Gospel. For these things certainly are not written that you may believe that Jesus Christ is the Father, but the Son. (Ibid.; emphasis mine)