The story of Jesus’s baptism in the gospel of John doesn’t actually say that John the Baptist baptized Jesus. However, there are so many points of contact between John and the synoptics (Matthew, Mark and Luke) that it’s hard to miss the point. John is so different from the other three gospels that when commonalities are found it’s the exception rather than the rule. All four gospels relate how John the Baptist claimed a connection to the words of Isaiah, “I am the voice crying out in the wilderness” (John 1:23||Isaiah 40:3). All four speak of John saying of Jesus that he is not worthy to untie the sandal ties of Jesus’s shoes (John 1:26). All four gospels emphasize that the baptism Jesus brings is different—it is a baptism of the Holy Spirit. The tradition that informed the synoptics informed John also.
The witness here is the role John played as essentially the last Old Testament prophet and the harbinger of the Messiah and the early church. We sometimes miss the radical claims of scripture that speak of the entrance of Christ as a planned and intentional act on the part of God. God sent John the Baptist to help us get ready. Jesus didn’t happen by accident. There was a plan—according to the New Testament.
What is unique in the Gospel of John is the confession of faith that he makes concerning Jesus. He said, “Here is the lamb of God who takes away the sin of the world.” In the Gospel of John, Jesus is not sentenced on Friday. He is sentenced on Thursday—John 19:14 says, “Now it was the day of Preparation for the Passover; and it was about noon.” That means that John places the beginning of the crucifixion at the same time as the time when the priests were beginning to slaughter lambs at the Temple. Thus, in his death, Jesus fulfilled the claim about him at the front end of the gospel. Jesus came to redeem us and free us of our sin.