Did the Messiah have to die?

With respect, we must also remember that it was God’s plan that the Messiah must die in order for the Jews to receive their promised reward.

Hebrews 9:15-17New Revised Standard Version Catholic Edition (NRSVCE)

15 For this reason he is the mediator of a new covenant, so that those who are called may receive the promised eternal inheritance, because a death has occurred that redeems them from the transgressions under the first covenant.[a] 16 Where a will[b] is involved, the death of the one who made it must be established. 17 For a will[c] takes effect only at death, since it is not in force as long as the one who made it is alive.

With that in mind, one of the possibilities for which God had provided, was that faithful Jews would kill the Messiah:

Deuteronomy 13:1-5New Revised Standard Version Catholic Edition (NRSVCE)

1 [a] If prophets or those who divine by dreams appear among you and promise you omens or portents, 2 and the omens or the portents declared by them take place, and they say, “Let us follow other gods” (whom you have not known) “and let us serve them,”

To the Jewish mind, Jesus was calling Himself God and they did not recognize Him. Therefore, they did right in putting Him to death.

5 But those prophets or those who divine by dreams shall be put to death for having spoken treason against the Lord your God—who brought you out of the land of Egypt and redeemed you from the house of slavery—to turn you from the way in which the Lord your God commanded you to walk. So you shall purge the evil from your midst.

Therefore, some of the Jews who killed Jesus Christ, did so out of allegiance and obedience to God.

John 5:18New Revised Standard Version Catholic Edition (NRSVCE)

18 For this reason the Jews were seeking all the more to kill him, because he was not only breaking the sabbath, but was also calling God his own Father, thereby making himself equal to God.

It was all part of God’s grand design in order to consummate the Old Testament and give the Old Testament Jews their promised reward.

John 11:49-52New Revised Standard Version Catholic Edition (NRSVCE)

49 But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all! 50 You do not understand that it is better for you to have one man die for the people than to have the whole nation destroyed.” 51 He did not say this on his own, but being high priest that year he prophesied that Jesus was about to die for the nation, 52 and not for the nation only, but to gather into one the dispersed children of God.