What is the purpose of the title "King of the Jews"?

To Christians then and today, Jesus was a descendant of King David, the fulfillment of Israel God's covenant with David who now rules forever from heaven, not only over Israel (the Jews) but also over all Christians (Jews and Gentiles). This is the meaning when the gospels use the term "King of the Jews". For example, Matthew mentions this at least 3 times:

• In the birth narrative, putting the words in the mouth of the Gentile Magi (cf. Matt 2:1-2)
• When Jesus rode on the donkey entering Jerusalem, as acclaimed by pious Jewish populace with the notable exception of many of Jerusalem's leaders (cf. Matt 21:1-11)
• In the crucifixion narrative, putting the words in the mouth of the Gentile Roman soldiers on the authority of Pilate (cf. Matt 27:27-44, John 19:19-22)

But to the Jews then and today, Jesus was a false messiah and a false teacher. Of course Jews then and today also deny that Jesus is their king, hence the protest of Jerusalem's religious leaders to Pilate who put the sign on the cross. To my knowledge, they are still waiting for the fulfillment of the Davidic covenant.

The unfortunate persecution of the Jews in Christian history shouldn't have happened, and in the past 70 years there have been much different view of the Jews by Christians of all denominations. Most Christians now don't blame the Jews for not accepting Jesus as their king, trusting that the God of Israel (as portrayed in the Hebrew Bible), which is also the God of Christians, will deal with the Jews as He sees fit. Some Christians (like the Catholic Church) leave open whether God continues to honor the covenants that He had with Israel before Jesus (see First Things 2005 article by Catholic theologian Avery Dulles The Covenant with Israel).

What is the purpose of the title: "King of the Jews"?

A week before Christ’s Passion he rode into Jerusalem while riding on a donkey. This definitely had meaning to the inhabitants of Jerusalem.

Jesus Rides Into Jerusalem On a Donkey To Shouts of Hosanna

11 And when they draw-near to Jerusalem— to Bethphage and Bethany, near the Mount of Olives— He sends-forth two of His disciples, 2 and says to them, “Go to the village before you. And immediately while proceeding into it, you will find a colt having been tied, on which none of mankind[a] yet sat. Untie it, and be bringing it. 3 And if someone says to you, ‘Why are you doing this?’, say, ‘The Lord has need of it, and immediately He sends it back here’”. 4 And they went and found a colt having been tied at a door, outside on the street. And they untie it. 5 And some of the ones standing there were saying to them, “What are you doing untying the colt?” 6 But the ones spoke to them just as Jesus spoke, and they permitted them. And they bring the colt to Jesus. 7 And they throw their cloaks on it, and He sat on it. 8 And many spread their cloaks on the road. And others spread leafy-branches, having cut them from the fields. 9 And the ones going ahead and the ones following were crying-out “Hosanna! Blessed is the One coming in the name of the Lord. 10 Blessed is the coming kingdom of our father David. Hosanna in the highest [heavens]!” - Mark 11:1-10

What could this possibly signify? Jesus became their King!

When Jesus rode into Jerusalem on a donkey, the Jews knew it meant.

When King David was very old, he wanted to establish his favored son Solomon as his successor. So he arranged for Solomon to ride on David's own mule, in the company of Zadok the priest and Nathan the prophet. 1 Kings 1:38 reports, "And Zadok the priest took an horn of oil out of the tabernacle, and anointed Solomon. And they blew the trumpet; and all the people said, God save king Solomon.'"

Later it is prophesied in Zechariah 9:9, "Rejoice greatly, O daughter of Zion; shout, O daughter of Jerusalem: Behold thy King cometh unto thee: He is just, and having salvation; lowly, and riding upon an ass, and upon a colt the foal of an ass."

Note that both in Solomon's case and Zechariah's prophecies, the man who is being proclaimed as the new king rides on a mule or ass's colt. The Jews knew the pattern.

At the end of Jesus' life, just before Passover, when he and his disciples were approaching Jerusalem, he sent two of them to borrow an ass and colt from a nearby village. People spread garments and branches along the way Jesus rode, saying "Hosanna to the son of David: Blessed is he that cometh in the name of the Lord;' And when he was come into Jerusalem, all the city was moved, saying Who is this?'" (Matthew 21:2).

In other words, all of nature understood the significance of the entry of the son of God into Jerusalem.

Matthew 21:15: "And when the chief priests and scribes saw the wonderful things that he did, and the children crying in the temple, and saying, Hosanna to the son of David'; they were sore displeased." To proclaim Jesus as the son of David was to suggest that he was the kingly successor.

In Matthew 21, when the chief priests and the elders asked him what authority he had, Jesus replied with parables that implied he was the king's son and that those who rejected him would be destroyed.

John 11:47-53: "Then gathered the chief priests and the Pharisees a council, and said, What do we? For this man doeth many miracles. If we let him thus alone, all men will believe on him: and the Romans shall come and take away both our place and nation.' The group took counsel together for to put him to death."

Thus the high priest prophesied that Jesus should die for the benefit of the people, and then the final events of Jesus' life began to come together.

When Jesus rode into Jerusalem on a donkey, the Jews knew it meant.

As fate would have it, when Pilate wrote Christ’s title and meaning for his execution, he wrote the truth!

The use of the term "King of the Jews" by the early Church after the death of Jesus was thus not without risk, for this term could have opened them to prosecution as followers of Jesus, who was accused of possible rebellion against Rome.

The final use of the title only appears in Luke 23:36–37. Here, after Jesus has carried the cross to Calvary and has been nailed to the cross, the soldiers look up on him on the cross, mock him, offer him vinegar and say: "If thou art the King of the Jews, save thyself." In the parallel account in Matthew 27:42, the Jewish priests mock Jesus as "King of Israel", saying: "He is the King of Israel; let him now come down from the cross, and we will believe in him.

Regardless if Pilate believe Jesus was the King of the Jews, he wrote what he wrote: Quod scripsi, scripsi.

The Latin title, being the official indictment, would undoubtedly have been written first on the board. This then would have determined the length of the board and/or the size of the letters required to fit the inscription into one line and for it still to be readable by the crowd from a distance (John 19:20).

In those days they did not use spaces between the words in any of the languages as we do now, and so John's Latin “title” contained just 26 letters and no spaces.

Luke's Greek “superscription” contained 30 letters, and so must have been written in slightly smaller letters than was the Latin. It is easy to see that there would not have been room for 16 more letters for the words “Jesus of Nazareth” (i.e. “Jesus the Nazarene”) in Greek.

Matthew's “accusation” in Hebrew contained just 19 letters, which is rather fewer than the two other languages, because the Jews did not write vowels in Hebrew. Whoever translated the title into Hebrew apparently did not think it worth adding “of Nazareth.” Perhaps he thought that to have lived in Nazareth was not an indictable offense!

If we put all of this together, it is highly probable that the board with the inscriptions looked as shown below, with the Latin written first, probably at the top, and then either the Greek or the Hebrew. - Why do all four Gospels contain different versions of the inscription on the Cross?