That's the Gospel. Jesus, the Son of God and Mary's Son, is the "I AM" who spoke to Moses, the Word through Whom all things were made in the beginning, despite the protestations of both ancient and modern Arians. The context in John 1 makes this clear. The rules of grammar make it clear in that section, as Pr. Fisk points out. And, Scripture makes this clear time and time again throughout. Today is the Feast Day of St. Thomas, Apostle. St. Thomas, upon seeing and touching our Resurrected Lord, declares, "My Lord and My God" (John 20:28). St. Paul refers to Jesus as "our great God and Savior" (Titus 2:13). St. Peter does the same (2 Peter 1:1). And, Jesus identifies Himself as God time and time again in the Holy Gospels. The Jews in His day knew exactly what He was saying of Himself. One of the reasons they wanted to kill Him is precisely because they knew that He was claiming to be Yahweh in the flesh, God Incarnate. You can't miss this. It's all over the place.
The irony is that heretics of old and present try to use the first verse of the Holy Gospel according to St. John to assert that Jesus isn't God, but a god, when the very purpose of that verse and all that follows it in that Gospel is to make vividly clear that Jesus is God. Already in St. John's day, there were heretics harassing the Church, claiming that Jesus wasn't God. St. John, inspired by the Holy Spirit, sets them straight. He is very clear. Jesus Is God. It is nothing short of amazing that anyone would try to deny that this is what St. John testifies. But, you know, heretics gonna heretic. That will never change until our great God and Savior, Jesus Christ, returns in great glory on the Last Day and the Truth is revealed to all.
Until then, may those of us who have been gifted with the faith to confess the truth about Jesus give thanks, rejoice, and cling to Him as our only source of rescue from sin, death, and the devil. May we ponder in our hearts, with Blessed St Mary, the Great and Mighty Wonder of God being born in our human flesh to bear our sins and be our Savior. May we, with the holy angels, marvel at this glorious mystery. May we, with St. Thomas, declare about Jesus, especially as we receive Him in the Holy Supper, "my Lord and my God!" Amen.