Answer
Before Jesus began His earthly ministry of proclaiming the coming kingdom, He went to the River Jordan to be baptized by John the Baptist (Matthew 3:13). Knowing that Jesus was the Messiah, John thought that he should be baptized by Jesus and not the other way around (Matthew 3:14). Jesus persuaded John to baptize Him, saying that it was time to fulfill all righteousness (Matthew 3:15).
It seems that there were two reasons for Jesus to say it was time to “fulfill all righteousness.” One reason immediately follows in the context, and one is rooted in an earlier biblical context. First, the baptism confirmed Jesus as the Messiah. Second, it confirmed John as the forerunner to the Messiah. Both Jesus and John were acting in fulfillment of prophecy.
When Jesus came up out of the water after being immersed (or baptized) by John, the Spirit of God descended like a dove from heaven upon Jesus (Matthew 3:16). And from the heavens was heard an audible voice that said, “This is my Son, whom I love; with him I am well pleased” (Matthew 3:17). Scripture prophesied that the Messiah would have the Spirit of God resting on Him (Isaiah 11:2) and He would be God’s Son (Isaiah 9:6; Mark 1:1). At Jesus’ baptism, both the Holy Spirit and the Father affirm that Jesus was the Messiah. The timing is significant. It was important that they made that affirmation after John baptized Jesus. Jesus recognized the significance of the moment even if John did not at first. Jesus recognized that the baptism was fitting—it was time to fulfill all righteousness (Matthew 3:15), and the way for Jesus and John to do that was by this particular baptism.
Baptism (from the Greek word baptize, which means “to immerse”) was a way for a person to identify with another person or group. It signified that the person being baptized was connected to the baptizer. When Jesus said it was time to fulfill all righteousness, it seemed that He understood there needed to be a formal, public connection of Jesus to John and vice versa. John had come proclaiming the good news of the kingdom and repentance (Matthew 3:2). Matthew acknowledged that John was the one whom Isaiah had prophesied would come to prepare the way for the Messiah (Matthew 3:3). Malachi had also recorded important prophecies about the Messiah and the one who would precede His coming. In one of those prophecies, God announced that His messenger would clear the path for Him, and then He would come to His temple (Malachi 3:1). When Jesus was baptized by John, it was a confirmation that John was that messenger, the forerunner to the Messiah.
John’s baptism of Jesus was an affirmation that John’s ministry was in accordance with God’s revealed plan. If John’s ministry was authentic, then the people should not ignore the One whom John was proclaiming: Jesus the Messiah. Jesus sought out John’s baptism because John was proclaiming the coming Messiah, and Jesus was that Messiah. By associating Himself with John and John’s message, Jesus affirmed both. He also showed the world that He, Jesus, was the prophesied Messiah. When the Holy Spirit and the Father made themselves known at this event, it showed that Jesus was the Messiah, and it affirmed the truth of John’s message.
Jesus later explained that John was one of the witnesses to His Messiahship (John 5:33–35). When Jesus said it was time to fulfill all righteousness (Matthew 3:15), He understood it was time for John’s ministry to be stamped as authentic and for the Messiahship of Jesus to be affirmed by John the Baptist, the Holy Spirit, and God the Father.
