The ESV translation of John 1:1 is as follows: “In the beginning was the Word, and the Word was with God, and the Word was God” (John 1:1). Perhaps a few comments will prove helpful.
The Greek preposition translated “with” (pros) often means “towards” or “to”, thereby pointing to the Word and God in face to face intimacy. The term “with” implies a strong sense of relationship. In some sense the Word is distinct and distinguishable from God and yet in another sense is God. In the Godhead in eternity past there was no solitude or isolation. There was complete togetherness. God is his own family.
John clearly declares that the Word is God. The Word who always was, the Word who always was with God, this Word was and is himself God. Although the Word is in some sense distinct from God, so too the Word and God are in some sense the same. John doesn’t say the Word was “like” or “similar to” or that he “bears a striking resemblance to” God. The Word was God. He doesn’t say the Word was a copy or facsimile of God or a reflection of God or merely analogous to God. The Word was God.
Therefore, whatever you can say about God the Father that pertains to his being God, you can say about the Word (God the Son; and God the Spirit as well). John isn’t saying there is something “divine” about the Word, as if he has some exalted, mystical, godlike qualities. He is God. The Word wasn’t an angel. The Word was God. The Word is in no sense, way, shape, or form inferior to God the Father.
So what are we to make of the insistence by Jehovah’s Witnesses that the absence of the definite article “the” requires that we translate the verse as: “and the Word was a god”? What follows may only make sense to those who know Greek, but I urge everyone to read it closely.
The absence of the Greek definite article (“the”) does not mean the Word is only one of perhaps many gods. In this kind of Greek construction where an anarthrous predicate nominative (one lacking the definite article), in this case theos or God, precedes the verb, the noun retains the emphasis of specificity or definiteness (i.e., “the” vs. “a”).
The apparent equation of subject and predicate nominative does not imply complete correspondence. The predicate nominative describes a larger category to which the subject belongs. Thus the verb “is” does not always mean “equals”.
I should also point out that when the article occurs with both the subject and predicate (which is not the case in John 1:1), both nouns are definite and interchangeable. When the nouns are not interchangeable, as here, the article is absent from the predicate (i.e., absent from the noun theos, God).
In other words, if John had included the article (“the” God) he would have contradicted himself. If he had said “the Word was the God” one would be led to conclude that the Word is all there is to God, that no being could be God except the Word. But John has already said the Word was with God. In other words, the Word isn’t all there is to God. There is also God the Father and God the Spirit.
So we see from this that there is both an excellent grammatical and theological reason why the definite article (“the”) does not appear with the noun “God”. And thus we are on solid ground when we affirm that John is declaring the Word, Jesus Christ, to be God.