One day, as he was teaching the people in the temple and telling the good news, the chief priests and the scribes came with the elders and said to him, “Tell us, by what authority are you doing these things? Who is it who gave you this authority?” He answered them, “I will also ask you a question, and you tell me: Did the baptism of John come from heaven, or was it of human origin?” They discussed it with one another, saying, “If we say, ‘From heaven,’ he will say, ‘Why did you not believe him?’ But if we say, ‘Of human origin,’ all the people will stone us; for they are convinced that John was a prophet.” So they answered that they did not know where it came from. Then Jesus said to them, “Neither will I tell you by what authority I am doing these things.” (Luke 20:1-8, NRSV)
Jesus usually didn’t answer a question with an answer, but more likely with another question. You see Jesus wanted to know where people were coming from and what their intentions were.
The leaders in the temple came to Jesus and asked Him where the authority He did the things He did came from. So He, wanting to know why they wanted to know this, asked where the baptism of John came from. If they said man, then He knew they were working the system and wanted to keep themselves in power rather than follow God, and if they said Heaven it would mean they wanted what God wanted. Even though they thought that He would ask why they weren’t baptized, or why they didn’t believe.
So they do not answer or say they do not know. So He does not tell them. But would they have listened or believed Him any how.
Jesus’ authority comes from the Father. So believe Him and follow after Him.