Summary: 1) The Confrontation (Matthew 21:23) 2) The Counter Question (Matthew 21:24–27) 3) The Characterization (Matthew 21:28–31a) & 4) The Connection (21:31b-32)
The road to hell is paved with good intentions is a proverb or aphorism. It is thought to have originated with Saint Bernard of Clairvaux who wrote, "L’enfer est plein de bonnes volontés et désirs" (hell is full of good wishes and desires) From our own experiences and observations we can see that many individuals may do bad things even though they intend the results to be good. A good example is the economic policies of the 1920s. These were intended to be a prudent response to the economic turmoil following World War I and the Wall Street Crash but they resulted in the Great Depression and World War II in which millions of people suffered and died.  Studies of business ethics indicate that most wrongdoing is not due directly to wickedness but is performed by people who did not plan to err. We rely on proper authorities in Government, the Military, Business, and other fields to exercise their expertise in things we do not have the day to day expertise. (http://en.wikipedia.org/wiki/The_road_to_hell_is_paved_with_good_intentions)
The question of proper authority was important for the Jews of the day. They held that they were the people of God, and they therefore detested their Roman overlords. Of necessity they submitted to them, but they did not believe that the Romans had the right to govern them. They were God’s own people, and their human lords were God’s high priest and those associated with him in the appointed assemblies, the great Sanhedrin and the lesser councils throughout the land. People like John the Baptist and Jesus presented problems because they did not fit into this picture. They were not like the Romans, who ruled unjustly but had the military backing that enforced their demands. And they were not like the high priests and other officials, who because of their official position were regarded as authoritative persons by official Judaism. What authority, then, did they have? (Morris, L. (1992). The Gospel according to Matthew (532–533). Grand Rapids, Mich.; Leicester, England: W.B. Eerdmans; Inter-Varsity Press.)
People in North America pride themselves on their own autonomy. , which is a word properly defined as the combination of auto (self) and nomos (law or authority). In essence, the more we become our own authority, or literally, law unto ourselves, we assume, the happier we seem to be.
In things of belief, regardless of our intentions, when we become our own authorities, we by definition, reject God and His authority.
In Matthew 21:23-32, the conflict in this encounter between Jesus and the religious leaders was over the issue of authority, specifically Jesus’ authority, which they questioned and which they feared would threaten their own positions of authority.
1) The Confrontation (Matthew 21:23)
Matthew 21:23 And when he entered the temple, the chief priests and the elders of the people came up to him as he was teaching, and said, "By what authority are you doing these things, and who gave you this authority?" (ESV)
These things took place on the way from Bethany to Jerusalem on Tuesday and Wednesday of Passover week (compare Mark 11:12–14, 20).
After Jesus and the disciples had passed the fig tree He cursed the day before and found it completely withered (vv. 18–22; cf. Mark 11:20–21), He entered the temple with them (Boice, J. M. (2001). The Gospel of Matthew (454). Grand Rapids, Mich.: Baker Books.).
The group of chief priests and the elders of the people may have included the high priests Caiaphas and Annas, who served concurrently for several years (Luke 3:2). Because of the seriousness of their confrontation of Jesus, it is likely that at least the captain of the Temple, the second highest official, was present. The elders of the people comprised a wide variety of religious leaders, which definitely included Pharisees (Matt. 21:45) and scribes (Luke 20:1), and possibly Sadducees, Herodians, and even some Zealots and Essenes. Although those groups had many differences from each other and were constantly disputing among themselves, they found common ground in opposing Jesus, because He threatened the authority of the entire religious establishment.
As He had the day before, when He so dramatically cleansed the Temple, Jesus now took center stage there again and was teaching as He walked about the courtyard (Mark 11:27). Jesus was teaching, no doubt, in one of the “porches,” “porticos” or “halls” of the temple. These porches were beautiful and huge. They were covered colonnades that ran all around the inside of the wall of the vast temple complex. Or, to put it differently, these halls were bounded on the outside by the temple wall, on the inside by the Court of the Gentiles (Hendriksen, W., & Kistemaker, S. J. (1953-2001). Vol. 9: New Testament commentary : Exposition of the Gospel According to Matthew. New Testament Commentary (776). Grand Rapids: Baker Book House.).