The Shepherd of Hermas, written between 85 and 145, said that Jesus Christ was the Spirit who was sent out in the beginning of creation: “The pre-existent Holy Spirit, which created the whole creation, God made to dwell in flesh that He desired” (Parable 5:6).
Explaining Luke 1:35, Justin Martyr, in 150, wrote, “It is wrong, therefore, to understand the Spirit and the power of God as anything else than the Word, who is also the first-born of God.”
In discussing “Pre-Nicene Theology,” in his Book Early Christian Doctrines, the Trinitarian theologian J.N.D. Kelly said, “the all but unanimous exegetical tradition of Luke 1:35 equated ‘the Holy Spirit’ and ‘the power of the Most High’ . . . to Christ Who, pre-existing as spirit or Word, was to incarnate Himself in her womb.”
But, J.N.D. Kelly was incorrect in saying that the early Church believed in the “incarnation” of Christ as we understand by Latin theology. The early Church believed that Christ was the Spirit “who was manifest in the flesh” ( 1 Timothy 3:16). The Shepherd of Hermas and the Epistle of Barnabas were two books written sometime before 150 and were included in the New Testament in the Codex Sinaiticus (325–360). Both Books explained that Christ was the Spirit “who was manifest in the flesh.” In fact, the Epistle of Barnabas used the phrase “manifest in the flesh” seven times.
Manifest in the flesh means that the Spirit of Christ only “appeared” in the Son of Man. The Spirit did not cease to exist outside of the Son of Man. This is not the idea of incarnation, which says the Spirit turned into a man. In the first Chapter of Genesis, the Spirit of Christ was only “found in appearance as a man”( Philippians 2:8 ) to create man after His image. Likewise, in the first Chapter of the New Testament, the same Spirit was only “found in appearance as a man” as Jesus Christ.
This idea was explained to us in the first Chapter of Revelation, where the Apostle John saw the Spirit of Christ appear and speak as “the Son of Man,” as the image of the invisible God (the Ancient of Days), as the Archangel WHO IS LIKE GOD, and as the Sanctified Body of Christ of the end days (The Rider on the White Horse).
The truth that God was trying to show us was that the Spirit of Christ can manifest itself in many different ways at the same time. For example, the Spirit of Christ can appear as the man Jesus Christ and as the image of the invisible God, at the same time. This is because the Spirit of Christ was only “found in appearance as a man.”
How was this original understanding of the Spirit of Christ lost?
After the Nicene Creed of 325, which began the Trinity doctrine, Emperor Constantine ordered the burning of books that opposed the Trinity doctrine.
Not only were books burned, but also key verses in the Bible were altered. One of the verses that was altered was 1 Timothy 3:16: “Who was manifest in the flesh.” This was changed to read: “God was manifest in the flesh.” Another significant verse that was changed was John 1:18, which called Christ the “only begotten God.” This was changed to “only begotten Son.”
There are also significant verses that have been changed by translators who believe in the Trinity. For example, God’s introduction of Himself as “I WILL BE WHO I WILL BE” in Exodus 3:14 was changed to “I AM WHO I AM.”
But perhaps the most significant verse that translators changed is John 1:1, which reads,
“In the beginning was the Word, and the Word was with God, and God was the Word.”
The Word was the Spirit who was first called “the Word” in Genesis 15:1. John’s meaning of “the Word” was clearly understood by the Jewish people, before Christ was born.
In the beginning, God, or rather “ELOHIM” in Genesis 1:1, was Jesus Christ. ELOHIM is the plural form of God in Hebrew. Christ became an ELOHIM, because when one God (EL) speaks for another, there are two Gods who speak.
Jesus imitated the greatest commandment when He said, “I and the Father are one”( John 10:30 ). “Yihvah our ELOHIM (I), Yihvah (the Father), ECHAD (are one)” ( Deuteronomy 6:4 ). In His defense, He told us that the word ELOHIM, in the Hebrew language, does not refer only to the Father, because even the Sons of God are called ELOHIM.
The Spirit of Christ was the “only begotten God” who appeared as the image of the invisible God and His speaker. He was the Word. He appeared as “the Messenger” or “Angel of Yihvah” to Jacob and He named Jacob “Israel.” Jacob called the Messenger of God, his God, saying, “the God who has fed me all my life long to this day, the Angel who has redeemed me from all evil” (Genesis 48:15–16 ).
The Spirit of Christ was the Angel, or ELOHIM, who appeared to Moses at the burning bush. He was Yihvah (HE WILL BE) ELOHIM, whom God called “the ELOHIM of Jacob” (Israel). He was Israel’s promised Redeemer, of whom God said, “I will save them by Yihvah their ELOHIM” ( Hosea 1:7 ). The Spirit of Christ was “manifest in the flesh” when HE WILL BE became “I AM.” The man Jesus Christ became God’s only begotten Son when He was resurrected as the firstborn from the dead, “as it is written in second Psalm, You are My Son, Today I have begotten You” ( Acts 13:33 ). Because Jesus Christ was obedient, even to the cross, He was made our Lord. And when all things are made subject to Him, then He will be made subject to God, that God may be all in all ( 1 Corinthians 15:28 ).
 First Apology, Chapter 33
 J.N.D. Kelly, Early Christian Doctrines, 1958, 5th rev. ed., London, p. 144