Ante-Nicene Fathers, Vol IX:
Epistle to Gregory and Origen's Commentary on the Gospel of John.: Chapter XV

15.  The Gospel is in the Old Testament, and Indeed in the Whole Universe.  Prayer for Aid to Understand the Mystical Sense of the Work in Hand.

As, then, we have shown that the beginning of the Gospel, according to one interpretation, is the whole Old Testament, and is signified by the person of John, we shall add, lest this should be called a mere unsupported assertion, what is said in the Acts 4526 about the eunuch of the queen of the Ethiopians and Philip.  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.  If he who preaches the Gospel preaches good things, and all those who spoke before the sojourn of Jesus in the flesh preach Christ, who is as we saw good things, then the words spoken by all of them alike are in a sense a part of the Gospel.  And when the Gospel is said to be declared throughout the whole world, we infer that it is actually preached in the whole world, not, that is to say, in this earthly district only, but in the whole system of heaven and earth, or from heaven and earth.  And why should we discuss any further what the Gospel is?  What we have said is enough.  Besides the passages we have adduced, passages by no means inept or unsuited for our purpose,—much to the same effect might be collected from the Scriptures, so that it is clearly seen what is the glory of the good things in Jesus Christ shed forth by the Gospel, the Gospel ministered by men and angels, and, I believe, also by authorities and powers, 4527 and thrones and dominions, and every name that is named, not only in this world, but also in the world to come, and indeed even by Christ Himself.  Here, then, let us bring to a close what has to be said before proceeding to read the work itself.  And now let us ask God to assist us through Jesus Christ by the Holy Spirit, so that we may be able to unfold the mystical sense which is treasured up in the words before us.

Footnotes

Acts viii. 26, sqq.

Ephes. i. 21.