"In the beginning was the Word, and the Word was with God, and the Word was God." The "Word" refers to Jesus (v17), the only begotten of the Father who became flesh and dwelt among us (v14). This affirms that Jesus is a separate individual from the Father (He was with God), and yet He Himself possesses Deity (He was God). Note that the context affirms both Jesus' Deity and His humanity: God became flesh and dwelt among us.
Some argue that the Greek "was God" has no definite article before "God," whereas there is a definite article in "with God." Hence, it is claimed that Jesus is god is a lesser sense, different from the Father. Hence, the "New World Translation" says, "the word was a god." However,
(1) All major standard translations say, "the Word was God." None say "a god." Hence they contradict the NWT. (See NKJV, KJV, ASV, NASB, RSV, NIV, etc.).
(2) If Jesus is "god" in a lesser sense than the Father, then we would have two different true gods! Clearly Jesus is not a false god; hence He is true God. But if He is "god" in a different sense than the Father, that would violate the passages saying there is one true God!
(3) Many Scriptures use "God" (Gk. theos) without an article to refer to the true God. See Matthew 5:9; 6:24; Luke 1:35,78; John 1:6,12,13,18; Romans 17:17; and many others.
(4) Many Scriptures use "God" both with and without an article in the same context, yet both uses clearly refer to the true God. See Matthew 4:3,4; 12:28; Luke 20:37,38; John 3:2; 13:3; Acts 5:29,30; Romans 1:7,8,17-19; 2:16,17; 3:5,22,23; 4:2,3; etc.
(5) The context of John 1:1-3 shows that Jesus is eternal and created all things. To call Him "God" in such a context must surely mean He is God in the same exalted sense as the Father.
(6) We will soon see other passages referring to Jesus as "God" using the definite article. If the NWT distinction is valid, then these passages must prove conclusively that Jesus is God in the same sense as the Father.
So John 1:1 refers to both Jesus and the Father as "God" in a context that affirms the eternal existence of Jesus and that He is the Creator of all (v1-3). This would be blasphemy if He does not possess Deity as the Father does.
[Marshall, Vine, Vincent, Lenski, Robertson, and other Greek scholars contend that the article is absent from "was God" in John 1:1, not to imply that Jesus was a "lesser god," but simply to identify "God" as the predicate nominative despite the fact it precedes the verb for emphasis (Colwell's Rule). If it had the definite article, that would imply that "the Word" and the Father are the same person. In any case, the Scriptures listed above clearly show that the lack of the article does not prove Jesus is God in a lesser sense than the Father.]