"But as the preaching of the Savior’s Gospel was daily advancing, a certain providence led from the land of the Ethiopians an officer of the queen of that country, for Ethiopia even to the present day is ruled, according to ancestral custom, by a woman. He, first among the Gentiles, received of the mysteries of the divine word from Philip in consequence of a revelation, and having become the first-fruits of believers throughout the world, he is said to have been the first on returning to his country to proclaim the knowledge of the God of the universe and the life-giving sojourn of our Savior among men; so that through him in truth the prophecy obtained its fulfillment, which declares that "Ethiopia stretches out her hand unto God."Eusebius
Early Church History Ch. 1. Vol 2

"Philip, it is said, began at the passage of Isaiah: “He was led as a lamb to the slaughter, and as a lamb before his shearer is dumb,” and so preached to him the Lord Jesus. How can he begin with the prophet and preach Jesus, if Isaiah was not a part of the beginning of the Gospel? From this we may derive a proof of the assertion made at the outset, that every divine Scripture is Gospel."Origen
Commentary on Gospel of John Bk. 1 Pt. 1 Ch. 15, Vol. 9

"And in that the living creatures are different in appearance, this is the reason: the living creature like to a lion designates Mark, in whom is heard the voice of the lion roaring in the desert. And in the figure of a man, Matthew strives to declare to us the genealogy of Mary, from whom Christ took flesh. Therefore, in enumerating from Abraham to David, and thence to Joseph, he spoke of Him as if of a man: therefore, his announcement sets forth the image of a man. Luke, in narrating the priesthood of Zacharias as he offers a sacrifice for the people, and the angel that appears to him with respect of the priesthood, and the victim in the same description bore the likeness of a calf. John the evangelist, like to an eagle hastening on uplifted wings to greater heights, argues about the Word of God."Victorinus
On the Apocalypse of John, Vol. 7

"But the beginning of the Gospel - for in respect of its extent it has a beginning, a continuation, a middle, and an end - is nothing but the whole Old Testament."Origen
Commentary on Gospel of John Bk. 1 Pt. 1 Ch. 15, Vol. 9

"Matthew he has made the following statements]: Matthew put together the oracles [of the Lord] in the Hebrew language, and each one interpreted them as best he could."Papias (Disciple of Apostle John)
Fragments Ch. VI, Vol. 1

"Concerning the four Gospels which alone are uncontroverted in the Church of God under heaven, I have learned by tradition that the Gospel according to Matthew, who was at one time a publican and afterwards an Apostle of Jesus Christ, was written first; and that he composed it in the Hebrew tongue and published it for the converts from Judaism. The second written was that according to Mark, who wrote it according to the instruction of Peter, who, in his General Epistle, acknowledged him as a son, saying, “The church that is in Babylon, elect together with you, saluteth you; and so doth Mark my son.” (1Pe_5:13) And third, was that according to Luke, the Gospel commended by Paul, which he composed for the converts from the Gentiles. Last of all, that according to John."Origen
Gospel of Matthew Vol. 9

"Matthew also issued a written Gospel among the Hebrews in their own dialect, while Peter and Paul were preaching at Rome, and laying the foundations of the Church. After their departure, Mark, the disciple and interpreter of Peter, did also hand down to us in writing what had been preached by Peter. Luke also, the companion of Paul, recorded in a book the Gospel preached by him. Afterwards, John, the disciple of the Lord, who also had leaned upon His breast, did himself publish a Gospel during his residence at Ephesus in Asia."Iranaeus
Against Heresies Bk. 3 Ch. I, Vol. 1