The confrontation with the moneychangers has been used to enlist Jesus into an ideological war against finance. There are many examples, but probably the best known of them is FDR's inaugural address in which he extensively referenced this text.
"Practices of the unscrupulous money changers stand indicted in the court of public opinion, rejected by the hearts and minds of men.
True they have tried, but their efforts have been cast in the pattern of an outworn tradition. Faced by failure of credit they have proposed only the lending of more money. Stripped of the lure of profit by which to induce our people to follow their false leadership, they have resorted to exhortations, pleading tearfully for restored confidence. They know only the rules of a generation of self-seekers. They have no vision, and when there is no vision the people perish.
The money changers have fled from their high seats in the temple of our civilization. We may now restore that temple to the ancient truths."
Is that really what this story means? Is it a general indictment of financial commerce? I don't think so.
We've been tracing Jesus' journey from Galilee down to Jericho into Judea and now to Jerusalem. The pattern has been that Jesus' denunciations of wealth coincide with two circumstances: proximity to Jerusalem and proximity to the ruling class. Jesus is toughest on accumulations of riches when in Judea, least so when in Galilee. He's tough on religious and political elites (often the same groups) who extract wealth, as opposed to those who create wealth through work, or even investment. That latter point - tolerance towards financial dealings - was counter-cultural in at least two ways. 'Conservative,' that is aristocratic, elites were tied to the land; the newly forming order of financial markets would have been somewhat alien to them.
David Fiensy makes this point in Christian Origins and the Ancient Economy,
The first thing we should say about the ancient economy of the Mediterranean and Middle Eastern regions is that it was agrarian. This observation is so common as to be beyond dispute.2 An agrarian economy was based on land ownership and farm production...the way to acquire wealth in an agrarian economy was to acquire more land. There was not much else a person could do with wealth but buy land. One could invest in trading and shipping, but it was risky. The culturally acceptable and economically less risky investment was land…
But Jesus tells several parables which involve finance, as opposed to agriculture. There is the Parable of the Unfaithful Steward, and the Parable of the Talents, both of which seem oriented towards a positive view of the investor. In fact, at least one, and probably both, of these parables put God in the role of the investor. This would be odd if Jesus thought of finance as an unrighteous profession.
Therefore, it is unlikely that Jesus' confrontation with the money changers was simply because they dealt with finance. Given Jesus' criticism of the temple and its elites, it seems more likely that their location on temple grounds was at least one part of His objection. The account specifies that He confronted them when He entered the temple, therefore they were on temple grounds. He specifically criticizes their presence there, contrasting it with Solomon's temple which was to be 'a house of prayer for all nations'. Instead, it had been turned into a "robbers' den" - a reference to Jeremiah who also criticized the temple elites of his time. The text makes clear that this activity taking place on temple grounds was an issue.
"And they came to Jerusalem. And He entered the temple and began to cast out those who were buying and selling in the temple, and overturned the tables of the moneychangers and the seats of those who were selling doves;
16 and He would not permit anyone to carry goods through the temple.
17 And He began to teach and say to them, "Is it not written, 'My house shall be called a house of prayer for all the nations '? But you have made it a robbers' den."
18 And the chief priests and the scribes heard this, and began seeking how to destroy Him; for they were afraid of Him, for all the multitude was astonished at His teaching."
(Mk. 11:15-18 NAS)
Mathew21:12 And Jesus entered the temple and cast out all those who were buying and selling in the temple, and overturned the tables of the moneychangers and the seats of those who were selling doves.
13 And He said to them, "It is written, 'My house shall be called a house of prayer'; but you are making it a robbers' den."
(Matt. 21:12-13 NAS)
I've highlighted several phrases to draw attention to some points which might be missed otherwise. One of them, I've already discussed, is the fact that the moneychangers were confronted after Jesus entered the temple, therefore they were on temple ground. Also, please note the phrase '"robber's den". I've already mentioned that this is borrowed from Jeremiah. But it's important to see how appropriate this designation was. Jesus calls this a robber's den because they are robbers. The temple system was dishonest in numerous ways, which we can discuss in great detail elsewhere.
One matter which stands out is the dishonest nature of the currency transactions. According to Alfred Edersheim's monumental tome, The Temple:
...But by far the largest sum was derived from the half-shekel of Temple tribute, which was incumbent on every male Israelite of age, including proselytes and even manumitted slaves. As the shekel of the sanctuary was double the ordinary, the half-shekel due to the Temple treasury amounted to about 1s. 4d. (two denarii or a didrachma). Hence, when Christ was challenged at Capernaum1 for this payment, He directed Peter to give the stater, or two didrachmas, for them both. This circumstance also enables us to fix the exact date of this event. For annually, on the 1st of Adar (the month before the Passover), proclamation was made throughout the country by messengers sent from Jerusalem of the approaching Temple tribute. On the 15th of Adar the money-changers opened stalls throughout the country to change the various coins, which Jewish residents at home or settlers abroad might bring, into the ancient money of Israel. For custom had it that nothing but the regular half-shekel of the sanctuary could be received at the treasury. On the 25th of Adar business was only transacted within the precincts of Jerusalem and of the Temple, and after that date those who had refused to pay the impost could be proceeded against at law, and their goods distrained,2 the only exception being in favour of priests, and that 'for the sake of peace,' that is, lest their office should come in disrepute…
So, the temple shekel was double weight, which no doubt had pious justifications about the glory - literally the heaviness - of the matters of God. But the bottom line is that worshippers had to pay twice the amount, due to dishonest weights and measures. And the mechanics of this financial abuse were carried out by the money changers. That is why Jesus calls them 'robbers'.
You may notice that I highlighted phraseology which singles out the dove merchants as particular objects of Jesus' ire. Matthew's and Mark's Gospels both mention the doves. Luke's account is generally similar but doesn't mention dove merchants.
John, however, focuses heavily on the dove sellers, so heavily that he portrays Jesus as speaking only to them.
15 And He made a scourge of cords, and drove them all out of the temple, with the sheep and the oxen; and He poured out the coins of the moneychangers, and overturned their tables;
16 and to those who were selling the doves He said, "Take these things away; stop making My Father's house a house of merchandise." (Jn. 2:15-16 NAS)
What is the significance of the doves? Under the Torah, the sacrifice of doves was a provision for the poor. Poor people bought doves. The whole system of money-changing was dishonest, but the dove sellers who charged double because of the dishonest shekel were specifically the group which was hurting the poor, such as were Joseph and Mary when they first started out.
"And when the days for their purification according to the law of Moses were completed, they brought Him up to Jerusalem to present Him to the Lord
23 (as it is written in the Law of the Lord, "Every first-born male that opens the womb shall be called holy to the Lord "),
24 and to offer a sacrifice according to what was said in the Law of the Lord, "A pair of turtledoves, or two young pigeons.""
(Lk. 2:22-24 NAS)
Luke doesn't mention doves, probably because his intended gentile audience would not understand this detail of Torah. But John has Jesus addressing only the dove-sellers. Why would John be particularly focused on the dove merchants? Remember John was probably the closest to Mary who, as we saw above, was herself exploited by this particular group. Jesus arranged for Mary to adopt John at the cross and according to early church historians, John and Mary stayed together, traveling to Ephesus.
This would also explain Jesus' anger. His own mother had been exploited by this system. Jesus called out religious leaders for devouring widow's houses. Perhaps He thought of his own, probably widowed mother. Jesus, on the other hand was not a devourer, but rather was Himself devoured by zeal for God and for the good of the people. That at least is how His disciples interpreted the confrontation with the dove merchants:
"and to those who were selling the doves He said, "Take these things away; stop making My Father's house a house of merchandise."
17 His disciples remembered that it was written, "Zeal for Thy house will consume me.""
(Jn. 2:16-17 NAS)
But Jesus was not the only one who was consumed. It was immediately after this incident that the chief priests and the scribes decided to destroy him.
"And the scribes and chief priests heard it, and sought how they might destroy him: for they feared him, because all the people was astonished at his doctrine." (Mk. 11:18 KJV)
There were consumed with fear at His popularity among the people. Up until then they had merely been irked by Jesus because of His challenge to their religion, but now He was challenging their money, and for that, He had to be murdered.