Why was john surprised when Jesus cam to be baptised?

Answer 1

I would not say that John was surprised that Jesus came to him to be baptised; even though John said to Jesus that he was not worthy to baptise him, (Matthew 3.14); for John told the people he would come. (Luke 3.16)

Answer 2

John was surprised that Jesus who was without sin would seek to come and be baptized, after all, it was sinners who needed baptism, NOT the sinless Son of God. John was calling for sinners to repent and be baptised. (Matt.3:2).

In Matt.3:11 John states ...."He who comes after me, is mightier than I, whose shoes I am not even worthy to carry.....". John's question comes from the apparent incongruity of an inferior person baptizing his superior, or in this case, the coming Saviour of mankind.

In Matt.3:13 it states that Jesus came to John at the Jordan river to be baptized by him, and in verse 14, it says "John forbade Him, saying, I have need to be baptized by You, and You are coming to me?". In John's eyes, it should have been the other way round.

While John was still in his mother's womb, God had chosen him for the specific ministry of calling people to repentance and baptism (Luke 1:13-17).

Jesus of course didn't need baptism, however, it was His way of identifying with mankind.