(Now they had been sent from the Pharisees.) They asked him, “Then why are you baptizing, if you are neither the Christ, nor Elijah, nor the Prophet?” John answered them, “I baptize with water, but among you stands one you do not know, even he who comes after me, the strap of whose sandal I am not worthy to untie.” These things took place in Bethany across the Jordan, where John was baptizing.That first phrase (verse 24) probably should have gone with the previous day's commentary. The "they" is referring to the "Jews" who were questioning John the Baptist.
(John 1:24-28, ESV)
John the Baptist's teaching was so bold and had such a messianic flare, that they couldn't help but wonder who he thought he was. To preach repentance would fall in line with there heritage of prophets that he was inheriting, but to preach the kingdom would be to preach a king.
John is making every attempt to take the attention and the focus off of himself and point it to the one who is coming after him. In a very real way, we should do something similar, except instead of pointing forward to one who is coming, we point back to the One who came (even though we know He is coming again).