John 1:1 says, “(a) In the beginning was the Word, (b) and the Word was with [the] God, (c) and the Word was God.”
That this Divine Word is none other than Jesus Christ is shown by verse 14, “And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.”
John 1:1a says the Word was in the beginning, but the beginning of what? It has to be the beginning of something. Was it the beginning of this world? Was it the beginning of the creation of the angels? Whichever beginning you place it at, it has to be the beginning of something.
Many Trinitarians use this to say that Christ has always been, and had no beginning. But that is not what the verse says. God had no beginning and has always existed! Also the Word “with” has to mean something. The Word was “with” God. They cannot be the same being, or one could not be with the other. As John 1:2 NIV says, “He [Jesus] was with God in the beginning.”
The proper rendering of John 1:1 into English from the original Koine Greek text continues to be a source of vigorous debate among Bible translators, and especially the phrase the Word was God (c). The first verse of John's Gospel says that God's Son Christ Jesus, being referred to as the Word here, was with God in the beginning, (a+b). John 1:1b does not say that the Messiah is God but was with “the” God. It is important to note that the word “the” exists in the Greek text and was left out by translators as they probably thought it read wrong, but it is correct and has purpose. Here is the original Greek text for (1b).
και and 2532 CONJ ο the 3588 T-NSM λογος Word 3056 N-NSM ην was 2258 V-IXI-3S προς with 4314 PREP τον the 3588 T-ASM θεον God 2316 N-ASM
The phrase “the God” identifies the one true God the Father in this verse and so the word “the” is important. While Jesus is called God in this verse, there is a clear distinction between Him and “the” God whom He was with. The God whom Jesus was with is “the” God the Father. Jesus was not the same God He was with but rather Jesus was God in the sense of being divine just like His Father, as being the Son, He inherits the characteristics of His Father. The Father is God and so His Son is God by nature just as any human by inheritance possesses the very nature and form of humanity.
One can better understand John 1:1 by using the same grammatical structure but with different subjects such as Adam and Eve for example. “In the beginning was the woman, and the woman was with [the] human, and the woman was human.” Adam is “the human” and the woman is Eve, but Eve is also human by nature but Eve is not “the human” in identity. They are two separate persons.
Look at this again with this perspective in mind. “In the beginning was the Word, and the Word was with the Deity, and the Word was Deity.” The Word, the Son was with the supreme Deity the Father, and the Word was Deity in nature. But the Son was not “the” Deity, the Son was not “the” Father, yet the Son has the Father's divine nature by inheritance. The Word has the same God quality, the same divine nature and the same God-ness as His Father.
Thus Jesus was with God in the beginning, but He is not “the” God the Father but God by inheritance and nature being the Son. He is God because He is the Son of God. It is that simple.
“Jesus is the only begotten Son of God. He was begotten, not created. HE IS OF THE SUBSTANCE OF THE FATHER, SO THAT IN HIS VERY NATURE HE IS GOD; and since this is so “it pleased the Father that in him should all fullness dwell.” Col. 1:19 ... While both are of the same nature, the Father is first in point of time. He is also greater in that he had no beginning, while Christ's personality had a beginning.” — (E.J. Waggoner, ST, April 8, 1889)