As John begins his gospel account, he begins with a description of the Word - Jesus, the pre-incarnate, Son of God, the second person of the Trinity and his role his creation and sustaining creation. John affirms throughout his gospel that Jesus is God, and this is where he begins. The gospel of John uses signs, witnesses and the very statements of Jesus himself to prove his identity as the second, eternal person of the godhead. This fact is undeniable throughout the gospel of John. This amazing fact has incredible implications for us. The Word, Jesus, came to earth as a man, took on flesh, to redeem us from our sins through his vicarious death on the cross for us. Jesus is God, and came to earth in the flesh as life and light for you. This is why advent (his coming) is for us. 

Throughout the Gospel of John we see the truth that Jesus is the promised one, the anointed one from God through his signs, witnesses, and statements; and he has come to rescue humanity from sin.