Who is Jesus
John starts his gospel with a much older description of Christ than Matthew and Luke give in their genealogies. John 1:1-5 places Christ in His rightful place. In the beginning was the Word, the Word was with God, and the Word was God. This declares boldly that Christ was God before He came to be on Earth as Jesus. It goes on to declare that Jesus was just as old as God. However old that is, it is drastically older than many can conceive.
Because John goes on to declare that Jesus had a part in the creation of all things. Literally nothing we can observe doesn't owe its existence to Jesus. And the oldest things we can see were created around 13.7 billion years ago, at the latest estimate, so that puts God as being around a very, very long time. Some estimates double that age. If that messes with your understanding of Genesis 1, read my comments on that chapter.
He then states a theme that really carries through much of the New Testament. Jesus is the life giver, both physically and eternally, and the life that He gives is the light of mankind. He came, shining in the darkness, and the darkness didn't understand His light. Some of that was due to the blinders that Satan put on people in the name of false religion, part of it was unbelief, part of it was traditions, and part of it was simply sin - pride, for example not thinking they needed a Savior.
Message of John the Baptist
John 1:6-18 declares the work of John the Baptist, who was sent before Christ to prepare the people to receive Him and His message. It was John the Baptist's heart that all glory should go to Jesus and none to his own ministry. It gives a very birds eye view of what Christ would go through.
First, that Christ would come into the world as a Light to overcome darkness. John reminds the readers that Jesus came into the world that He made, but the world He created didn't recognize Him. Even the people who knew Him didn't accept His life and ministry to any great extent. But those that did receive His ministry Jesus Christ gave power to do not only the works that He did in His ministry, but greater works, because He was risen.
These believers were born again, after the first birth of their mother, but of God to be alive in Him and witnesses to the world. In verse 14, John gives a one verse summary of Christ's life. He was made flesh, 100% man, emptying Himself of His divine Godly nature and powers while on the earth. This had never been done by God before and would never need to be done again!. He lived a life full of the grace of God and 100% truth. There was no sin in Him, being born of Mary and God, and thus He could be completely full of truth and righteousness to be the perfect sacrifice for our sin to bridge the gap between the best that we could be, which admittedly isn't great, and the perfect holiness that God demands.
As John encountered Jesus in his travels around Galilee, John declared Jesus to be the one that the whole Old Testament had pointed to. You can go back to immediately after the fall of man and see the prophecy given in Genesis 3:15 of Adam and Eve's seed eventually destroying the plans of Satan and of Satan physically killing Christ, although Satan couldn't hold Him in the grave (Isaiah 53:10). John knew his place. He knew that for all the attention he had been getting in his ministry of repentance and water baptism, that Jesus, the one he was declaring to the people, was the only one of importance. He declares that not only should Jesus be preferred before his ministry, but that Jesus was eternal, existing long before John ever came on the scene. Jesus is the true source of grace from God. He could satisfy, where the law of Moses was just a shadow of things to come.
He further declares in John 1:18 that while man hasn't seen God's full glory at any time, and indeed wasn't on the scene for the vast majority of God's existence, Jesus was present with god all the time. One of Jesus' jobs on earth was to show the nature and nurture of God to their generation, and He did so wonderfully. Much of John's gospel is an accounting of this nature to the people around Him. Not since God walked with Adam and Eve in the garden of Eden had humanity had the chance to observer God close up. Jesus provided this to man, and the disciples and others wrote it down for us to benefit from.
John Answers the Religious
The religious of the Jewish faith noticed John's ministry. They saw how the people were holding him up and flocking to him. And somewhere, deep in their hearts, they knew that God had something to do with what was going on in the desert so they came to ask questions of John the Baptist.
They demanded, in John 1:19-27, for him to identify himself, because they were expecting a messiah at any time and wanted to know if John was that expected messiah. He told them flat out that he wasn't the Christ that they were expecting. Then they wanted to know if he was Elijah, because it had been foretold that Elijah would come before the messiah was made known (Malachi 4:5-6). Elijah shall indeed come back before the second advent, along with Enoch, to usher in the final rule of Christ in the millennium and to denounce the anti-Christ in Jerusalem before that, and to warn the inhabitants of the city, and indeed the world, to straighten up and choose Christ, being killed by the anti-Christ and resurrected on the third day as a sign that all that happened 2,000 or so years ago was real. But John the Baptist was only moving and operating in the spirit of Elijah, and wasn't Elijah come back from heaven. He had the same message to the Jews that Elijah had to the Jews of his day - "Make straight the way of the Lord". Stop your sinning. Turn to God.
They then wanted to know the purpose of his baptisms. This baptism in water was a sign of accepting a new path in their religion that they didn't accept or approve of. Indeed, water baptism would come to set Jews and their baptized relatives apart. Families would split due to rejecting the Jewish faith. The water baptism was an outward sign that you couldn't hide from the public that you had chosen to become a Christian.
John ends this section by declaring that one of the spectators who was standing among them wasn't someone they knew, but John was made aware by the Spirit that He was present, and the John was unworthy to even take His shoe off. Would that all Christians today understood just how worthy and Holy God is. I'm pretty sure we would all try harder to live up to Christian standards in everything we do if we truly had the humility and understanding of John the Baptist that he was even unworthy to take off the shoe of the man Christ, let alone do anything in the presence of God the Father.
Baptism of Christ
John 1:28-34 records Jesus coming to John while John was baptizing his followers in the Jordan river. John immediately identifies Christ to the people around him as the Lamb of God who would end up being the sacrifice for sin and taking all of the world's sin upon His shoulders, as it were, and freeing anyone who would chose His sacrifice and turn to Him from its terrible burden.
John the Baptist bears record of the events of Jesus baptism, that the Spirit of God came down from heaven like a dove where it abode on Christ, which was the identification that God had told John He would use to identify the person who would baptize with that self-same Holy Ghost. John bare record that this was indeed the Son of God to all of those around him. Who can we bear record to that Jesus has come in the flesh, walked in the Spirit, was crucified, and rose again three days later? The message hasn't changed for 2,000 years, and God still wants us to be spreading the message to all the people we know.
Selection of Andrew, Simon Peter, Philip and Nathanael
In John 1:35-51, we have the calling of the first few disciples. John the Baptist identified Christ to the people he was with, and two of them who heard him identify Christ followed Christ. One of these was Andrew, and he leads them to Simon Peter who also chooses to follow Christ. Never doubt the power of an invitation. Christ renames Simon, the son of Jona, Cephas, which is interpreted as a stone. We need to pray that we will all be the good interpretation of stone for Christ - a firm foundation. We don't want to be a dead weight good for nothing but ballast!
Philip is called next, and Philip goes to find Natnanael. He proclaims that they have found the messiah who they were looking for in Nazareth, being the son of Joseph. Nathanael is skeptical that anything good can come out of Nazareth and says so. And yet, at the invitation, he comes to see for himself. When he approaches Christ, Christ gives him a quick character evaluation, as being an Israelite without guile or deceit. This surprises Nathanael, because he knows that Christ has never met him. But Christ speaks of where Philip encountered him, saying that He had seen him in the Spirit while he was sitting under the fig tree.
When Nathanael is converted by this simple statement, Jesus replies that he should hang onto his seat because he hasn't seen anything yet (paraphrasing just a bit). We need to have the same simple faith of Nathanael today. Will Christ find faith when He returns (Luke 18:8)? That's a grand question. It seems that faith is getting shakier and shakier for many people of the world and many Christians today. That's because we are relying on earthly things that change, break, and let us down. We need to have the faith of Nathanael in a God that is unchanging, who always keeps His promises if we meet the conditions He has placed on them, and will ultimately come through in the best way for us, regardless of what we think might be best. Praise the name of the Lord!