https://www.gotquestions.org/the-Word-was-with-God.html

Answer
The opening verses of John’s gospel are perhaps the most theologically packed writings in all the Bible: “In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning” (John 1:1–2). These words and the concepts they express form the foundation for John’s entire gospel, which was written to prove that Jesus Christ is God’s incarnate Son.
The term translated “Word” is Logos in the Greek language. John uses it here as an unmistakable reference to Jesus Christ. The Hebrews often referred to God in terms of His powerful word (Psalm 33:6; 107:20). With a few simple statements, John declares that Jesus, like His heavenly Father, has always existed since the beginning of time. Jesus was with God in the beginning because He is God, and He always has been.
Right out of the gate, John presents the doctrine of the deity of Christ and affirms His co-eternal nature with God as Creator of the universe (John 1:3). To his first-century, Greek-speaking audience, John communicates straightforward truths that don’t require explanation. But for current-day Bible readers, the expression the Word was with God hides a vital truth about the relationship between God and Jesus. No single English equivalent exists to better express the full meaning of the word with in the phrase.
In English, we typically understand the preposition with to mean “near” or “beside.” But the original Greek term expresses a living, active union in the closest, most intimate sense. When John said, “The Word was with God,” he meant that the divine Word—Jesus Christ—was not only present alongside God from all eternity but was in a living, dynamic, co-equal relationship of close communion with Him. The Holman New Testament Commentary explains, “The Greek word is pros which literally means ‘toward,’ implying a face-to-face relationship” (Gangel, K., Broadman & Holman, 2000, Vol. 4, p. 9).
The relationship between God and Jesus is eternal and intimately personal…