The account of Jesus begins in the Gospel of John with these words.
John 1:1 In the beginning was the Word, and the Word was with God, and the Word was fully God.
John was an old man when he finally sat down to write the words you just read. He had had many years to ponder the mystery of Jesus. The Holy Spirit had given him insight and understanding as he grew deeper in the Lord. Finally, at the age of 90 he was prepared to write.