In the beginning the Word already existed. The Word was with God, and the Word was God. God created everything through him, and nothing was created except through him.
John 1:1‭-3 NLT

Who is “the Word”? It is apparent from the following verses that it is referring to Jesus Christ. If the words sound a little familiar, we may be reminded of Genesis 1:1-2.

In the beginning God created the heavens and the earth. The earth was formless and empty, and darkness covered the deep waters. And the Spirit of God was hovering over the surface of the waters.
Genesis 1:1‭-‬2 NLT

John the apostle, who wrote the book of John, was one of Jesus’ closest disciples, and is telling us that God the Son was there with God the Father and God the Holy Spirit at creation. Not three Gods, but three in one.