There’s not a kingdom gospel for Jews and the gospel of grace for the gentiles.
The fact is there is only ONE gospel of the kingdom of Christ and of God, offered first to the Jew, then to the gentile:
Rom 1:16 For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek.
Gal 3:28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
All that both Paul and Jesus taught applies to us, too, as proven by Paul, the apostle to the gentiles, preaching the kingdom:
Act 20:24 But none of these things move me, neither count I my life dear unto myself, so that I might finish my course with joy, and the ministry, which I have received of the Lord Jesus, to testify
the gospel of the grace of God.
Act 20:25 And now, behold, I know that ye all, among whom I have gone
preaching the KINGDOM of God, shall see my face no more.
Paul taught the gospel of grace and the kingdom, both. He didn’t just teach the Jews that Jesus is the messiah, he taught He is the messiah who came to die for our sins, and that God raised Him from the dead:
Act 13:26 Men and brethren, children of the stock of Abraham, and whosoever among you feareth God, to you is the word of this salvation sent.
Act 13:27 For they that dwell at Jerusalem, and their rulers, because they knew him not, nor yet the voices of the prophets which are read every sabbath day, they have fulfilled them in condemning him.
Act 13:28 And though they found no cause of death in him, yet desired they Pilate that he should be slain.
Act 13:29 And when they had fulfilled all that was written of him, they took him down from the tree, and laid him in a sepulchre.
Act 13:30 But God raised him from the dead:
Act 13:31 And he was seen many days of them which came up with him from Galilee to Jerusalem, who are his witnesses unto the people.
Act 13:32 And we declare unto you glad tidings, how that the promise which was made unto the fathers,
Act 13:33 God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee.
Act 28:30 And Paul dwelt two whole years in his own hired house, and received all that came in unto him,
Act 28:31 Preaching the KINGDOM of God, and teaching those things which concern the Lord Jesus Christ, with all confidence, no man forbidding him.
Paul preached the same thing to both the Jews and the Greeks/gentiles- there was no difference:
Act 20:20 And how I kept back nothing that was profitable unto you,but have shewed you, and have taught you publickly, and from house to house,
Act 20:21
Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.
There is only gospel of the kingdom of Christ - not a kingdom gospel and a gospel of grace.
And Peter in Acts 2 preaches the death burial and resurrection of Jesus to the Jews there on Pentecost, too.
Act 2:22 Ye men of Israel, hear these words; Jesus of Nazareth, a man approved of God among you by miracles and wonders and signs, which God did by him in the midst of you, as ye yourselves also know:
Act 2:23 Him, being delivered by the determinate counsel and foreknowledge of God, ye have taken, and by wicked hands have crucified and slain:
Act 2:24 Whom God hath raised up, having loosed the pains of death: because it was not possible that he should be holden of it.