Matthew 3v14

But John forbad him, saying, I have need to be baptized of thee, and comest thou to me?

This verse is immediately after the previous one studied, where Jesus came to John asking to be baptised. Here we see that John recognises (again, see also verse 11 {4 }) that there is a greater baptism to be had from Jesus than the one that John is administering. John also reveals here that he personally felt the lack of the baptism of the Holy Ghost and fire that he had talked about earlier, as we saw in verse 11 {4 }. John desired the baptism that Jesus would later give, yet it was Jesus who asked for the baptism that John was administering.

As we will see in later sections, John had the special gift of discerning the sins of the people that came to him – for evidence of this see especially Luke 3v10-15 {32 }. In this instance John’s gift seems to be showing him that Jesus had no sin, way before it was documented in scriptures such as 1^st Peter 2v22, Hebrews 4v15, Hebrews 9v28, and 2^nd Corinthians 5v21. In John’s mind this lack of sin – ie righteousness – meant that Jesus had no need to repent of sin.

As Jesus lived his whole life without sin, and baptism included repentance (see v6, v12, Mark 1v4, Acts 2v38 etc) then we could ask the question “Why did Jesus repent of sin that He didn’t have?” Jesus answers this question in the next verse: “it becometh us to fulfil all righteousness” (v15). By His statement, Jesus is letting us know some of the reasons behind why He was baptised.

Whatever the law requires concerning righteousness, Jesus was starting to fulfil. Although He would later sacrifice His perfect blood for us on the cross, paying the price for our sin (Romans 5v9-11), His baptism was still a necessary step on the way.
Jesus fulfils the righteousness that we need – at least part of this we get from being baptized.
Through baptism we identify with the righteousness of Jesus, and receive it spiritually from Him.
All righteousness stems from and grows out of this act of Jesus’
If Jesus needs baptism for the sake of righteousness, then surely we who are not without sin need it more.
Even Jesus’ repentance is perfect, where ours sometimes isn’t. We can therefore look to Him as our example.
Jesus makes what we need available before we even know that we need it.

Where our repentance fails or is imperfect in some way, Jesus can make up the difference for us.