Why is the Gospel of John said to present Jesus distinctively as "the Son of God"?

15 The man went away, and told the Jews that it was Jesus who had made him well. 16 For this reason the Jews were persecuting Jesus, because He was doing these things on the Sabbath. 17 But He answered them, “My Father is working until now, and I Myself am working.” 18 For this reason therefore the Jews were seeking all the more to kill Him, because He not only was breaking the Sabbath, but also was calling God His own Father, making Himself equal with God. JN 5:15-18

When one studies the book of John and writes down the main ideas. One can easily conclude that John wants the readers to know who Jesus is and who He claimed to be. In the passage above we learn that Jesus called God His Father. This meant something very specific in this day and time and the audience clearly understood what this meant as they tried to kill Him.

Although Mark only contains about 7 direct and indirect specific references to Jesus as the Son of God, this short gospel possibly places greater emphasis on Jesus as the Son of God than any other New Testament gospel, with its opening words containing this description of Jesus (*):

Mark 1:1: The beginning of the gospel of Jesus Christ, the Son of God;

The audience of Mark's Gospel is kept aware throughout that Jesus is the Son of God. In contrast, Mark does not specifically refer to Jesus as Servant, although all four gospels do include echoes of the Suffering Servant passages in the Book of Isaiah. There are at least 14 references to Son of Man, comparable to the approximately 26 references in the much longer Gospel of Luke.

John does contain at least 25 references to Jesus as the Son of God, which is nearly double the number (13) in Matthew and substantially more than in the other gospels, but this gospel does not emphasise this relationship in the way Mark's Gospel does. It also contains more than double the number of references to Jesus as King of the Jews than any other gospel.

Interestingly, while there are only about 5 references in Matthew, I count at least 11 references in John to Jesus as King of the Jews, including the dramatic account of Pontius Pilate insisting on this being placed on the sign at the crucifixion:

John 19:19-22: And Pilate wrote a title, and put it on the cross. And the writing was, JESUS OF NAZARETH THE KING OF THE JEWS. This title then read many of the Jews: for the place where Jesus was crucified was nigh to the city: and it was written in Hebrew, and Greek, and Latin. Then said the chief priests of the Jews to Pilate, Write not, The King of the Jews; but that he said, I am King of the Jews. Pilate answered, What I have written I have written.

In the same way as Mark uses its prologue to identify Jesus as the Son of God, John uses the prologue to identify him as the Word (Logos):

John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.

The concept that Jesus Christ is the Word has been important in establishing the doctrine of Jesus' divinity, as well as that of the Trinity. But many scholars are aware that the synoptic gospels did not see Jesus as God. For example, Rhoads, Dewey and Michie say in Mark as Story, page 104, that in Mark, Jesus is the son of God, not by virtue of a special birth or a divine nature - he becomes God's son at his baptism and is neither God nor a divine being. In Matthew and Luke, Jesus is the son of God by virtue of a special birth, but he is not yet God. So, it is only in John's Gospel that Jesus is fully divine. Throughout John's Gospel, there are references that point to Jesus as divine, including his use of the term "I am" that in Greek was understood to mean 'God'.

So, compared to any other gospel, John's Gospel has around twice as many references to Jesus as either King of the Jews or as Son of God, but the real emphasis is on Jesus' divinity.

(*) Some early manuscripts, including Sinaiticus, omit 'Son of God' in Mark 1:1, so there is no certainty that the phrase is original to Mark's Gospel.

John's first chapter introduces the divinity of Jesus.

1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was in the beginning with God. 3 All things came to be through him, and without him nothing came to be. What came to be 4 through him was life, and this life was the light of the human race; 5 the light shines in the darkness, and the darkness has not overcome it.

There's more, but the theme is established early on.

He tells us that "in the beginning was God, the Word was with God and the Word was God". He is telling us Jesus is God. God with us in the flesh.

The book of John further states that "the Word became flesh". Who is the Word? Who became flesh? Jesus. He was the Son of God because he was born in the flesh, but was also divine. God put on the flesh of man, to sacrifice Himself for our sins.

Let's not put God in a box; He created everything in the world; He certainly allowed His Spirit to develop in the flesh of a woman and come into this world. John's Gospel is emphatically telling us that Jesus wasn't just a man, He is God!

Jesus defied all the earthly, physical definitions of the ability of a man. He walked on water, he made wine from water, he did miracle.s, healed the sick, made the lame to walk, the blind to see. He announced Himself to all that He was sent from God to do the things that God wanted. However, he's speaking in third person about himself. He came to be the once and for all sacrifice for mankind; there was no other "being without blemish" that could be this sacrifice. God no longer wanted the blood of bulls and goats. His sacrifice is the ONLY sacrifice and the final sacrifice for us. There is no other sacrifice for us.

John's purpose was to reiterate Jesus' divinity as God, His purpose for mankind and that He was obedient toward His end to be a sacrifice. If one seeks to understand the scriptures, God will give you understanding and open your mind to the deeper insight of John's and the other Gospels as well as the entire Bible.