Overview
There are really two aspects to this question.
- Did Pilate believe Jesus was King of the Jews?
- What was the consequence of Pilate declaring Jesus to be the King of the Jews?
By way of comparison, Pilate believed Jesus was innocent and Barabbas was guilty. His beliefs did not change the significance of his decisions: Jesus was crucified and Barabbas was set free.
Pilate's position was appointed by Ceasar; he was not answerable to the Senate. If the people disapproved of his decisions, they could appeal to his superior, the legate of Syria. In fact, Pilate was removed from office when the people protested to Lucius Vitellius the Elder over his handling of the Samaritan revolt.
However, from 22AD to 33AD Lucius Aelius Lamia, who had been appointed as legate of Syria was detained in Rome and never personally ruled in Syria. Effectively only Pilate ruled during this period. For example, he could have replaced Caiaphas as the high priest as Vitellius did shortly after removing Pilate.
The King of the Jews
John describes the issue before Pilate is whether Jesus is King of the Jews.
John 18 (NKJV)
33 Then Pilate entered the Praetorium again, called Jesus, and said to Him, “Are You the King of the Jews?” 34 Jesus answered him, “Are you speaking for yourself about this, or did others tell you this concerning Me?”
35 Pilate answered, “Am I a Jew? Your own nation and the chief priests have delivered You to me. What have You done?”
36 Jesus answered, “My kingdom is not of this world. If My kingdom were of this world, My servants would fight, so that I should not be delivered to the Jews; but now My kingdom is not from here.”
37 Pilate therefore said to Him, “Are You a king then?”
Jesus answered, “You say rightly that I am a king. For this cause I was born, and for this cause I have come into the world, that I should bear witness to the truth. Everyone who is of the truth hears My voice.”
38 Pilate said to Him, “What is truth?” And when he had said this, he went out again to the Jews, and said to them, “I find no fault in Him at all.
Frederic Louis Godet explains the significance of this exchange:
There is a distinction to be made here, not ot the thought of Pilate, but f that of Jesus. In the political sense of the term king of the Jews, the only one known to Pilate, Jesus might reject this title; but in a religious sense which every believing Jew gave to it and in which was equivalent to Messiah, Jesus must accept it whatever the consequences of this avowal might be. 1
As Godet states for Pilate King of the Jews is a political title. For Jews the title belongs to the Messiah, the Davidic king who will rule the Jewish people in the Messianic Age.
Pilate's Decree
John 19 (NKJV)
19 Now Pilate wrote a title and put it on the cross. And the writing was:
JESUS OF NAZARETH, THE KING OF THE JEWS
20 Then many of the Jews read this title, for the place where Jesus was crucified was near the city; and it was written in Hebrew, Greek, and Latin.
21 Therefore the chief priests of the Jews said to Pilate, “Do not write, ‘The King of the Jews,’ but, ‘He said, “I am the King of the Jews.” ’ ”
22 Pilate answered, “What I have written, I have written.”
The chief priests objected to Pilate's wording because as the ranking Roman official his rulings mattered. Whether Pilate believed Jesus was the King of the Jews did not change the significance of his decision to declare Jesus was the King of the Jews. Just as declaring an innocent man guilty and a guilty man innocent, there was a legal significance to Pilate's declaration.
The chief priest's could appeal Pilate's decision, but the issue would be moot in a few hours. Pilate declared Jesus to be the King of the Jews and he executed Him for that reason. In essence, what Pilate wrote was an official Roman affirmation Jesus was the Messiah.
It is unlikely Pilate believed Jesus was King of the Jews either as a political or religious title. That did not alter the legal significance of his decree.
Jesus answered him, “You would have no authority over me at all unless it had been given you from above... (John 19:11)
- Frederic Louis Godet, Commentary on John's Gospel, Kredel Publications, 1978, p. 928