And they which were sent were of the Pharisees.
And they asked him, and said unto him, Why baptizest thou then, if thou be not that Christ, nor Elias, neither that prophet?
Verse 24 clarifies that it was the Pharisees who had sent the priests and Levites to question John. It was a never a good thing for anyone to be investigated by the Pharisees, who always, always believed and proclaimed that they and they alone had authority to bless or to curse the ministry of any upstart preachers.
Verse 25 reveals their real question: “If you are not Christ, nor Elijah, nor that prophet that shall come, then how do you have authority to baptize anyone?”
The Pharisees were educated men. They studied the scriptures. They knew the Torah. They knew tradition right down to the dotted i’s and crossed t’s.
What they didn’t know, though, was the most important prophecy of all: The coming of the Lord, Jesus Christ. They wanted a strong king who would deliver them from the Romans, and so they closed their eyes and hearts to the idea of anyone of such lowly brith could be possibly be the One Who would save them from Rome.
In memorizing tradition, they missed the biggest blessing of all. What’s worse, they took great pride in not being fooled.