That all things were created by God, and that there is no creature which exists but has derived from Him its being, is established from many declarations of Scripture; those assertions being refuted and rejected which are falsely alleged by some respecting the existence either of a matter co-eternal with God, or of unbegotten souls, in which they would have it that God implanted not so much the power of existence, as equality and order. For even in that little treatise called The Pastor or Angel of Repentance, composed by Hermas, we have the following: First of all, believe that there is one God who created and arranged all things; who, when nothing formerly existed, caused all things to be; who Himself contains all things, but Himself is contained by none. (Book I, Chapter 3, Part 3)

In English the text by Hermas is most widely known as The Shepherd. It had quasi-canonical status prior to the Council of Nicea and appears in bibles as late as the 4th Century.

Origen is almost certainly referring to The Shepherd as a paradoxical source of support for his trinitarian doctrine. He is using a popular - but for him mistaken - book, saying in effect, even Hermas supports my position.

In fact Hermas is inconsistent. While the quotation above anticipates the orthodoxy that would eventually emerge. In another passage a Son of God is described as a good man filled with a "pre-existent spirit" and adopted as the Son.

The Holy Pre-existent Spirit. Which created the whole creation, God made to dwell in flesh that He desired. This flesh, therefore, in which the Holy Spirit dwelt, was subject unto the Spirit, walking honorably in holiness and purity, without in any way defiling the Spirit. When then it had lived honorably in chastity, and had labored with the Spirit, and had cooperated with it in everything, behaving itself boldly and bravely, He chose it as a partner with the Holy Spirit; for the career of this flesh pleased [the Lord], seeing that, as possessing the Holy Spirit, it was not defiled upon the earth. He therefore took the son as adviser and the glorious angels also, that this flesh too, having served the Spirit unblamably, might have some place of sojourn, and might not seem to have lost the reward for its service; for all flesh, which is found undefiled and unspotted, wherein the Holy. (The Shepherd, Parable V)

The image is from the catacombs at Rome.