The first non-canonical instalce of a “rule of faith” appears twice in the writing of Ignatius of Antioch. The first, shown below, is in his Epistle to the Trallians, ch 9 (additional material that appears in the longer Greek recension is included below in brackets). The second instance appears in his letter to the Christians at Smyrna.

Be deaf, therefore, when any would speak to you apart from (at variance with) JESUS CHRIST
[the Son of God],
who was descended from the family of David,
born of Mary,
who truly was born
[both of God and of the Virgin …
truly took a body; for the Word
became flesh and dwelt among us
without sin …],
ate and drank [truly],
truly suffered persecution under Pontius Pilate,
was truly [and not in appearance]
crucified and died …
who was also truly raised from the dead [and rose after three days],
his Father raising him up …
[and after having spent forty days with the Apostles,
was received up to the Father,
and sits on his right hand,
waiting till his enemies are put under his feet].

Κωφώθητε οὖν, ὅταν ὑμῖν χωρὶς Ἰησοῦ Χριστοῦ λαλῇ τις
[τοῦ υἱοῦ τοῦ Θεοῦ]
τοῦ ἐκ γένους [γενομένου] Δαβὶδ
τοῦ ἐκ Μαρίας,
ὃς ἀληθῶς ἐγεννήθη
[καὶ ἐκ θεοῦ καὶ ἐκ παρθένου …
ἀληθῶς ἀνέλαβε σῶμα· ὁ Λόγος
γὰρ σὰρξ ἐγένετο καὶ ἐπολιτεύσατο
ἄνευ ἁμαρτίας …],
ἔφαγέν τε καὶ ἔπιεν [ἀληθῶς],
ἀληθῶς ἐδιώχθη ἐπὶ Ποντίου Πιλάτου,
ἀληθῶς [δὲ, καὶ οὐ δοκήσει] ἐσταυρώθη
καὶ ἀπέθανεν …
ὃς καὶ ἀληθῶς ἠγέρθη ἀπὸ νεκρῶν [καὶ ἀνέστη διὰ τριῶν ἡμερῶν],
ἐγείροντος αὐτὸν τοῦ Πατρὸς αὐτοῦ …
[καὶ τεσσαράκοντα ἡμέρας συνδιατρίψας τοῖς Ἀποστόλοις,
ἀνελήφθη πρὸς τὸν Πατέρα·
καὶ ἐκάθισεν ἐκ δεξιῶν αὐτοῦ,
περιμένων ἕως ἄν τεθῶσιν οἱ ἐχθροὶ αὐτοῦ ὑπὸ τοὺς πόδας αὐτοῦ].

From Schaff, Creeds V.II P.11-12

For those who are curious, here is the version from Smyr.:
Smyr. 1:1   I glorify Jesus Christ, the God who made you so wise, for I observed that you are established in an unshakable faith, having been nailed, as it were, to the cross of the Lord Jesus Christ in both body and spirit, and firmly established in love by the blood of Christ, totally convinced with regard to our Lord that he is truly of the family of David with respect to human descent, Son of God with respect to the Divine will and power, truly born of a virgin, baptized by John in order that all righteousness might be fulfilled by him, 2 truly nailed in the flesh for us under Pontius Pilate and Herod the tetarch (from its fruit we derive our existence, that is, from his divinely blessed suffering), in order that he might raise a banner for the ages through his resurrection for his saints and faithful people, whether among Jews or among Gentiles, in the one body of his church.
Smyr. 2:1   For he suffered all these things for our sakes, in order that we might be saved;[98] and he truly suffered just as he truly raised himself—not, as certain unbelievers say, that he suffered in appearance only (it is they who exist in appearance only!). Indeed, their fate will be determined by what they think: they will become disembodied and demonic.
Smyr. 3:1   For I know and believe that he was in the flesh even after the resurrection; 2 and when he came to Peter and those with him, he said to them: “Take hold of me; handle me and see that I am not a disembodied demon.” And immediately they touched him and believed, being closely united with his flesh and blood. For this reason they too despised death; indeed, they proved to be greater than death. 3 And after his resurrection he ate and drank with them like one who is composed of flesh, although spiritually he was united with the Father.

Tral. 9:1 Κωφώθητε οὖν, ὅταν ὑμῖν χωρὶς Ἰησοῦ Χριστοῦ λαλῇ τις, τοῦ ἐκ γένους Δαυίδ, τοῦ ἐκ Μαρίας, ὅς ἀληθῶς ἐγεννήθη, ἔφαγέν τε καὶ ἔπιεν, ἀληθῶς ἐδιώχθη ἐπὶ Ποντίου Πιλάτου, ἀληθῶς ἐσταυρώθη καὶ ἀπέθανεν, βλεπόντων τῶν [98] ἐπουρανίων καὶ ἐπιγείων καὶ ὑποχθονίων· 2 ὅς καὶ ἀληθῶς ἠγέρθη ἀπὸ νεκρῶν, ἐγείραντος αὐτὸν τοῦ πατρὸς αὐτοῦ, ὅς καὶ κατὰ τὸ ὁμοίωμα [99] ἡμᾶς τοὺς πιστεύοντας αὐτῷ οὕτως ἐγερεῖ ὁ πατὴρ αὐτοῦ ἐν Χριστῷ Ἰησοῦ, οὗ χωρὶς τὸ ἀληθινὸν ζῆν οὐκ ἔχομεν.

From Gregory Nazianzus, “Second Theological Oration”, IX, p.291-2

IX. And thus we see that God is not a body. For no inspired teacher has yet asserted or admitted such a notion, nor has the sentence of our own Court allowed it. Nothing then remains but to conceive of Him as incorporeal. But this term Incorporeal, though granted, does not yet set before us—or contain within itself His Essence, any more than Unbegotten, or Unoriginate, or Unchanging, or Incorruptible, or any other predicate which is used concerning God or in reference to Him. For what effect is produced upon His Being or Substance3445 by His having no beginning, and being
incapable of change or limitation? Nay, the whole question of His Being is still left for the further consideration and exposition of him who truly has the mind of God and is advanced in contemplation. For just as to say “It is a body,” or “It was begotten,” is not sufficient to present clearly to the mind the various objects of which these predicates are used, but you must also express the subject of which you use them, if you would present the object of your thought clearly and adequately (for every one of these predicates, corporeal, begotten, mortal, may be used of a man,
or a cow, or a horse). Just so he who is eagerly pursuing the nature of the Self-existent will not stop at saying what He is not, but must go on beyond what He is not, and say what He is; inasmuch as it is easier to take in some single point than to go on disowning point after point in endless detail, in order, both by the elimination of negatives and the assertion of positives to arrive at a comprehension of this subject. But a man who states what God is not without going on to say what He is, acts much in the same way as one would who when asked how many twice five make, should answer, “Not two, nor three, nor four, nor five, nor twenty, nor thirty, nor in short any number below ten, nor any
multiple of ten;” but would not answer “ten,” nor settle the mind of his questioner upon the firm ground of the answer. For it is much easier, and more concise to shew what a thing is not from what it is, than to demonstrate what it is by stripping it of what it is not. And this surely is evident to every one.

“X. Now since we have ascertained that God is incorporeal, let us proceed a little further with our examination. Is He Nowhere or Somewhere. For if He is Nowhere, then some person of a very inquiring turn of mind might ask, How is it then that He can even exist? For if the non-existent is nowhere, then that which is nowhere is also perhaps non-existent. But if He is Somewhere, He must be either in the Universe, or above the Universe. And if He is in the Universe, then He must be either in some part or in the whole. If in some part, then He will be circumscribed by that part which is less than Himself; but if everywhere, then by one which is further and greater—I mean the Universal, which contains the Particular; if the Universe is to be contained by the Universe, and no place is to be free from circumscription. This follows if He is contained in the Universe. And besides, where was He before the Universe was created, for this is a point of no little difficulty. But if He is above the Universe, is there nothing to distinguish this from the Universe, and where is this above situated? And how could this Transcendence and that which is transcended be distinguished in thought, if there is not a limit to divide and define them? Is it not necessary that there shall be some mean to mark off the Universe from that which is above the Universe? And what could this be but Place, which we have already rejected? For I have not yet brought forward the point that God would be altogether circumscript, if He were even comprehensible in thought: for comprehension is one form of circumscription.”

36. Through the Holy Spirit comes our restoration to paradise, our ascension into the kingdom
of heaven, our return to the adoption of sons, our liberty to call God our Father, our being made
partakers of the grace of Christ, our being called children of light, our sharing in eternal glory, and,
in a word, our being brought into a state of all “fulness of blessing,” both in this world and in
the world to come, of all the good gifts that are in store for us, by promise hereof, through faith,
beholding the reflection of their grace as though they were already present, we await the full
enjoyment. If such is the earnest, what the perfection? If such the first fruits, what the complete
fulfilment? Furthermore, from this too may be apprehended the difference between the grace that
comes from the Spirit and the baptism by water: in that John indeed baptized with water, but our
Lord Jesus Christ by the Holy Ghost. “I indeed,” he says, “baptize you with water unto repentance;
but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost and with fire.” Here He calls the trial at the judgment the baptism of
fire, as the apostle says, “The fire shall try every man’s work, of what sort it is.” And again,
“The day shall declare it, because it shall be revealed by fire.” And ere now there have been
some who in their championship of true religion have undergone the death for Christ’s sake, not
in mere similitude, but in actual fact, and so have needed none of the outward signs of water for
their salvation, because they were baptized in their own blood. Thus I write not to disparage
the baptism by water, but to overthrow the arguments of those who exalt themselves against the
Spirit; who confound things that are distinct from one another, and compare those which admit of
no comparison.”

(Basil, “On the Holy Spirit”, xv.36 & 38, In Schaff, NPNF 2.08, p.22-23)

He says as much in Genesis: “In the beginning God created the heavens and the earth”; and again through that most helpful book The Shepherd, “Believe thou first and foremost that there is One God Who created and arranges all things and brought them out of non-existence into being.” Paul also indicates the same thing when he says, “By faith we understand that the worlds were framed by the Word of God, so that the things which we see now did not come into being out of things which had previously appeared.” For God is good—or rather, of all goodness He is Fountainhead, and it is impossible for one who is good to be mean or grudging about anything. Grudging existence to none therefore, He made all things out of nothing through His own Word, our Lord Jesus Christ; and of all these His earthly creatures He reserved especial mercy for the race of men. Upon them, therefore, upon men who, as animals, were essentially impermanent, He bestowed a grace which other creatures lacked—namely the impress of His own Image, a share in the reasonable being of the very Word Himself, so that, reflecting Him and themselves becoming reasonable and expressing the Mind of God even as He does, though in limited degree, they might continue forever in the blessed and only true life of the saints in paradise. But since the will of man could turn either way, God secured this grace that He had given by making it conditional from the first upon two things—namely, a law and a place. He set them in His own paradise, and laid upon them a single prohibition. If they guarded the grace and retained the loveliness of their original innocence, then the life of paradise should be theirs, without sorrow, pain or care, and after it the assurance of immortality in heaven. But if they went astray and became vile, throwing away their birthright of beauty, then they would come under the natural law of death and live no longer in paradise, but, dying outside of it, continue in death and in corruption. This is what Holy Scripture tells us, proclaiming the command of God, “Of every tree that is in the garden thou shalt surely eat, but of the tree of the knowledge of good and evil ye shall not eat, but in the day that ye do eat, ye shall surely die.” “Ye shall surely die”—not just die only, but remain in the state of death and of corruption.

Source: Athanasius, On the Incarnation rev. ed, trans. by a Religious of C.S.M.V. (Crestwood, NY: Saint Vladimir’s Seminary Press, 1996).

“10. At what season does the Saviour rise? Is it the season of summer, or some other? In the same Canticles immediately before the words quoted He says, The winter is past, the rain is past and gone; the flowers appear on the earth; the time of the pruning is come. Is not then the earth full of flowers now, and are they not pruning the vines? Thou seest how he said also that the winter is now past. For when this month Xanthicus is come, it is already spring. And this is the season, the first month with the Hebrews, in which occurs the festival of the Passover, the typical formerly, but now the true. This is the season of the creation of the world: for then God said, Let the earth bring forth herbage of grass, yielding seed after his kind and after his likeness. And now, as thou seest, already every herb is yielding seed. And as at that time God made the sun and moon and gave them courses of equal day (and night), so also a few days since was the season of the equinox.

At that time God said, let us make man after our image and after our likeness. And the image he received, but the likeness through his disobedience he obscured. At the same season then in which he lost this the restoration also took place. At the same season as the created man through disobedience was cast out of Paradise, he who believed was through obedience brought in. Our Salvation then took place at the same season as the Fall: when the flowers appeared, and the pruning was come.

11. A garden was the place of His Burial, and a vine that which was planted there: and He hath said, I am the vine! He was planted therefore in the earth in order that the curse which came because of Adam might be rooted out. The earth was condemned to thorns and thistles: the true Vine sprang up out of the earth, that the saying might be fulfilled, Truth sprang up out of the earth, and righteousness looked down from heaven. And what will He that is buried in the garden say? I have gathered My myrrh with My spices: and again, Myrrh and aloes, with all chief spices. “Now these are the symbols of the burying; and in the Gospels it is said, The women came unto the sepulchre bringing the spices which they had prepared: Nicodemus also bringing a mixture of myrrh and aloes. And farther on it is written, I did eat My bread with My honey: the bitter before the Passion, and the sweet after the Resurrection. Then after He had risen He entered through closed doors: but they believed not that it was He: for they supposed that they beheld a spirit. But He said, Handle Me and see. Put your fingers into the print of the nails, as Thomas required. And while they yet believed not for joy, and wondered, He said unto them, Have ye here anything to eat? And they gave Him a piece of a broiled fish and honeycomb. Seest thou how that is fulfilled, I did eat My bread with My honey.”

From Cyril of Jerusalem, Catechetical Lectures, Lecture XIV, “On the words, and rose from the dead on the third day, and ascended into the heavens…” chapter 10. (In Schaff NPNF v 2.7, 216-217)

“And we afterwards continually remind each other of these things. And the wealthy among us help the needy; and we always keep together; and for all things wherewith we are supplied, we bless the Maker of all through His Son Jesus Christ, and through the Holy Ghost. And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability, and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons. And they who are well to do, and willing, give what each thinks fit; and what is collected is deposited with the president, who succours the orphans and widows and those who, through sickness or any other cause, are in want, and those who are in bonds and the strangers sojourning among us, and in a word takes care of all who are in need. But Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead. For He was crucified on the day before that of Saturn (Saturday); and on the day after that of Saturn, which is the day of the Sun, having appeared to His apostles and disciples, He taught them these things, which we have submitted to you also for your consideration.”

Justin Martyr, First Apology, Chapter LXVII.—Weekly worship of the Christians (from Schaff, ANF 1, p.185-6)