John makes it clear to his readers that Jesus is eternal and He is deity.
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. (John 1:1-2)
John takes our minds back to the beginning - “In the beginning God created the heavens and the earth” (Genesis 1:1).
The Word is Eternal
When “the beginning” occurred - the “Word” was already in existence. He predates time.
“The Word (always) existed, he was (always) with God (later identified as the Father), and the Word (always) was God, i.e., deity in nature.” - Jackson, A New Testament Commentary
Jesus is not “a god.” He is not a created being. He is eternal, deity, and the Creator of all things.
All things were made through Him, and without Him nothing was made that was made. In Him was life, and the life was the light of men. (John 1:3-4)
Life is in the Word
Life was not given to Him - as it was given to you and me. Life is “in Him.” Life comes from Him - He is the life-giver.
Jesus said to her, "I am the resurrection and the life. He who believes in Me, though he may die, he shall live. (John 11:25)
Jesus said to him, "I am the way, the truth, and the life. No one comes to the Father except through Me. (John 14:6)
Life is Given in the Word’s Name
John wrote so that we would believe (and obey - John 14:15) Jesus - the Word.
And truly Jesus did many other signs in the presence of His disciples, which are not written in this book; but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name. (John 20:30-31)