There are many interesting facets to the Sahidic Coptic translation of John's Koine Greek text at chapter 1, verses 1-18.
In verse one, it has been noted that the anarthrous Greek text's KAI QEOS HN hO LOGOS is rendered with the Sahidic Coptic indefinite article. This is significant, because the Coptic could have left the text without any article, or could have used the definite article, if the translators had so understood the verse. While a noun without any article is infrequent in Sahidic Coptic, there are examples of this in the Nag Hamadi corpus of works. It is to be observed, therefore, that the Coptic translators found that verse one did not identify the Logos with the Person hO QEOS. Rather, the Logos is qualitatively QEOS.
Verse fourteen is a strong affirmation in both the Greek and the Coptic texts that the Logos was incarnate in the man Jesus Christ. This was a refutation of some of the Gnostic teachings of that time. The heavenly Word, Logos, did become human, "flesh," and lived among mankind in order to perform his salvific work.
Verse eighteen is the subject of various theories. Coptic scholar and translator George W. Horner suggested in 1911 that in this verse the translators combined the variant readings of the Greek texts at their disposal. Others have suggested that they may possibly have used only one Greek text, perhaps one that read hO MONOGENHS QEOS (as in p75 or some mss. of Sinaiticus), where both QEOS and hUIOS can be adduced -- hUIOS by implication from -GENHS. The later Bohairic version of verse eighteen reads closer to that found in p66 and Vaticanus, and in many modern critical texts. But the Sahidic Coptic translators lived and worked at a time -- the 2nd or 3rd century C.E. -- when believers wished to grasp the meaning of the Logos as both QEOS and hUIOS.
The Johannine Prologue expresses the primitive faith that the one known as the Lord Jesus Christ was divine in his origin, even as he was human in his work. In Jesus, divine intervention reached into the human situation and transformed it anew, producing a regeneration, a re-creation, finally opening the way for God's loving-kindness to manifest itself fully in the world.