The phrase gospel of the kingdom & references to “the kingdom of God” and “the kingdom of heaven”
Vine's Expository Dictionary of New Testament Words: [ 1,,G932, basileia ] KINGDOM
"The fundamental principle of the Kingdom is declared in the words of the Lord spoken in the midst of a company of Pharisees, "the Kingdom of God is in the midst of you," Luke 17:21, marg., that is, where the King is, there is the Kingdom.
Kingdom - Vine's Expository Dictionary of New Testament Words
OT Gospel of the Kingdom: Israel only! Preaching begins with John the Baptist 25-26AD, is retired 70AD/Temple destroyed. Will be reinstated after the catching-up of the Church (Thes 4)
NT Gospel of the GRACE of God: Begins with Paul's return from Arabia (Gal 1) 35-37AD & is still operating. Will be retired at the catching up-up of the Church (Thes 4)
There is one Gospel (Galatians 1:6-9), so the Gospel of the Kingdom is the same as the Gospel of grace.
The Kingdom of God is composed of citizens who are children of Abraham and inheritors of the promise through faith.
In Matthew 4:15-23, Jesus began his ministry with the Gospel message to repent for the Kingdom of God is at hand, which as a light to the Gentiles, and God's law was how his audience knew what sin is (Romans 3:20), so repenting from our disobedience to it is a central part of the Gospel of the Kingdom, which is in accordance with Jesus being sent in fulfillment of the promise to bless us by turning us from our wickedness (Acts 3:25-26), which is the Gospel of the Kingdom that was made known in advance to Abraham in accordance with the promise (Galatians 3:8), which he taught to Gentiles in Haran in accordance with the promise (Genesis 12:1-5).
In Genesis 18:19, God knew Abraham that he would teach his children and those of his household to walk in His way by doing righteousness and justice that the Lord may bring to him all that He has promised. In Genesis 25:4-5, God will multiply Abraham's children as the stars in the heaven, to his children He will give all of these lands, and through his children all of the nations of the earth will be blessed because he heard God's voice and guarded His charge, commandments, statutes, and laws. In Deuteronomy 30:16, if the children of Abraham will love God with all of their heart by walking in God's way in obedience to His statutes, commandments, and laws, then they will live and multiply and God will bless the in the land that they go to possess, so the promise was made to Abraham and brought about because he walked in God's way in obedience to His law, he taught his children and those of his household to do that, and because they did that.
In Psalms 119:1-3, God's law is how the children of Abraham knew how to be blessed by walking in His way, and in John 8:39, Jesus said that if they were children of Abraham, then they would be doing the same works as him, so the way that the children of Abraham are multiplied and are a blessing to the nations in accordance with inheriting the promise through faith is through spreading the Gospel of the Kingdom by turning the nations from their wickedness and teaching them to do that same works as Abraham by walking in God's way in obedience to His law.
In Psalms 119:29, he wanted to put false ways far from him, for God to be gracious to him by teaching him to obey His law, and he chose the way of faithfulness by setting it before him, so this has always been the one and only way of salvation by grace through faith. In Exodus 33:13, Moses wanted God to be gracious to him by teaching him to walk in His way that he might know Him and Israel too, and in John 17:3, eternal life is knowing God and Jesus, so this is also the Gospel of grace.
A glimpse of God's promised coming Kingdom to ISRAEL:
2 Sam 7:12-13, 1 Chron 17:10-14, Isa 9:6-7,11:1-9, Dan 2:44,7:13-14, Mic 4:1-5, Zec 14:1-21, Lk 1:32-33.
All the above OT verses are coming kingdom promises God made to ISRAEL'S fathers (Rom 15:8). Necessary context in understanding the kingdom messaging. (Matt 3:2).
Matt 15:24 Messiah answered & said, I am not sent but unto the lost sheep of the house of Israel.
(SCRIPTURE PROCLAIMS: Jesus was sent, ONLY, to the lost sheep of the "House of Israel")
Rom 15:8 I say that Messiah was a minister of the circumcision for the truth of God, to confirm the promises made unto the fathers:
(SCRIPTURE PROCLAIMS: Jesus was sent to minister to the circumcision/JEWS. To fulfil OT promises made to the ISRAEL'S fathers)
In Matthew 24:12-14, Jesus prophesied that the Gospel of the Kingdom would be proclaimed to all nations, and in Matthew 28:16-20, he commissioned his disciples to bring the Gospel to all nations teaching everything that he taught them, so while Jesus taught the Gospel to the Jews first, this was so Jews would be equipped for the role of being a light and a blessing to the nations by spreading it to them.
A/the new covenant/testament doesn't/can't begin until after Jesus (the testator) dies.
Heb 9:
16 For where a testament is, there must also of necessity be the death of the testator.
17 For a testament is of force after men are dead: otherwise it is of no strength at all while the testator liveth.
(MY NOTE: Jesus taught, lived, kept, & fulfilled old covenant Mosaic laws. There is no new covenant until after Jesus (the Testator) dies.
Jesus did not establish the New Covenant for the purpose of negating anything that he spent his ministry teaching, but rather the New Covenant still involves following the Mosaic Law in accordance with the Gospel of the Kingdom (Jeremiah 31:33).
Eph 2:
11 Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
(SCRIPTURE PROCLAIMS: Pre-death & resurrection, gentiles were: ""strangers living outside covenant seals of promise"" ""having no hope"" living without God in the world)
13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
(SCRIPTURE PROCLAIMS: But NOW/post death & resurrection. The blood of Christ has brought you near.)
In Ephesians 2:12-19, through faith in Christ, Gentiles are no longer strangers to the covenants of promise or aliens, but are fellow citizens of Israel along with the saints in the household of God, which is all in accordance with the Gospel of the Kingdom.
Acts 10 records the dispensational message change. From the OT ALL JEWISH gospel of the kingdom promise. To the NT gospel of the GRACE of God message.
The NT good new/gospel of the GRACE of God (void Mosaic law adherence (Acts 15). Is open to ALL, Jew & gentile.
(MY NOTE: These gentiles don't repent of anything, don't bring a animal sin offering, adhere to any
TODAY'S NT gospel of the GRACE of God message is: Jesus died for your sins, was buried & rose on the 3rd day (1 Cor 15:1-4) for your justification (Rom 4:25)
He accepts every true seeker that approaches with a contrite heart. At acceptance Jesus gives the convert GIFTS: His Holy Spirit (Acts 10:45, 11:17), A declaration of righteousness (Rom 4:5 & 5:17-18) & eternal life (Rom 6:23, Jn 5:24).
The NT Gospel of grace does not make void the Mosaic Law, but rather it involves God being gracious to us by teaching us to obey it. In Titus 2:11-13, our salvation is described as being trained by grace to do what is godly, righteous, an good, and to renounce doing what is ungodly, so God graciously teaching us to obey the Mosaic Law is the content of His gift of salvation. Furthermore, in Titus 2:14, Jesus gave himself to redeem us from all lawlessness and to purify for himself a people of his own possession who are zealous for doing good works, so the way to believe in 1 Corinthians 15:1-4 is by becoming zealous for doing good works in obedience to the Mosaic Law (Acts 21:20). Furthermore, in Ezekiel 36:26-27, the Spirit has the role of leading us to obey the Mosaic Law under the New Covenant.