Jesus gives us a clear mission statement early on in his ministry. “I must preach the good news of the Kingdom of God to the other cities also; for I was sent for this purpose” (Luke 4:43, RSV). The word translated “good news” in the NT is the word evangelion, also translated “gospel.” It is unarguable that Jesus here defines his purpose: To preach the Gospel of the Kingdom of God.
“It may be said that the teaching of Jesus concerning the Kingdom of God represents his whole teaching. It is the main determinative subject of all his discourse.”
This is radical and astonishing when one considers that the “orthodox” definition of the Gospel says nothing at all about the Kingdom that Jesus came to preach! The public has been offered a gospel based only on the death, burial, and resurrection of Jesus (“DBR”) for the sins of the world. Vital as the DBR is to the Gospel it simply cannot be the whole story.
Now after John had been taken into custody, Jesus came into Galilee, preaching the gospel of God, and saying, “The time is fulfilled, and the Kingdom of God is at hand; repent and believe in the gospel” (Mark 1:14, 15). Not a word about his death, at this stage.
The very first words of Jesus Christ, in Matthew, concern the Kingdom. Moreover, he equates the Gospel with believing in the Kingdom of God. Jesus’ first commandment in the book of Mark is to believe that the Kingdom of God is coming and to repent. Jesus never stopped preaching this Kingdom Gospel.
“Jesus was going throughout all Galilee, teaching in their synagogues and proclaiming the Gospel of the Kingdom, and healing every kind of disease and every kind of sickness among the people” (Matt. 4:23).
Jesus traveled from place to place proclaiming this Good News of the coming Kingdom without a hint of his death, burial and resurrection. It is not until Matthew 16:21 that Jesus begins to teach about his death and resurrection. And when he does, the disciples don’t even believe him! How could they have been preaching the forgiveness of sin through Christ’s death yet? They could not have, because they had heard nothing about it.
In Mark 9:31 Jesus instructs his disciples about what is about to happen to him. “For he was teaching his disciples and telling them, ‘The Son of Man is to be delivered into the hands of men, and they will kill him; and when he has been killed, he will rise three days later.’” At this point, when he introduced his disciples to DBR, it still wasn’t public knowledge or part of the Gospel. Verse 32 goes on to make this clear: “But they did not understand this statement, and they were afraid to ask him.” The disciples did not understand. And again, in Luke 9:45 they did not understand. They could not have been preaching something they did not understand themselves. It was only after Jesus had been raised that they began to understand. What then did Jesus commission them to preach?
“And he sent them out to proclaim the Kingdom of God and to perform healing” (Luke 9:2). “Departing, they began going throughout the villages, preaching the Gospel and healing everywhere” (Luke 9:6). Jesus sent them out to proclaim the Kingdom of God before they knew anything about the DBR. Note: preaching the Gospel is directly connected to the Kingdom message.
One might ask: After his resurrection, did the Gospel message change from one about the Kingdom to one solely about the DBR? We find that this is not the case. “To these he also presented himself alive after his suffering, by many convincing proofs, appearing to them over period of forty days and speaking of the things concerning the Kingdom of God” (Acts 1:3). Clearly the Gospel was still centered on the Kingdom. For forty days the disciples underwent an intensive “seminar” on the Kingdom of God taught by the King himself.
“His great concern was that men would be led to make that irrevocable decision for the kingdom which would bring them into the present sphere of its saving power so that they would be prepared to enter the kingdom when it should finally come.” 
It would be strange to think that the very mission of Jesus would be rejected or glossed over by his personally trained disciples. A change of Gospel is the very opposite of what we see in the book of Acts. After his conversion Paul was dedicated to the same message which had preoccupied Jesus.
“He entered the synagogue and continued speaking out boldly for three months, reasoning and persuading them about the Kingdom of God” (Acts 19:8).
“The continuity between Jesus’ and Paul’s Gospel is unmistakably clear and may be traced throughout Luke’s report of the early Church: Apostolic practice is uniformly to propagate the Message about the Kingdom.” 
Not for a moment did Paul abandon the Gospel of the Kingdom to proclaim the Gospel of the grace of God. They are the same thing! Compare Acts 20:24 and 25: “But none of these things move me, nor do I count 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. And now, behold, I know that all of you, among whom I have gone preaching the Kingdom of God, shall see my face no more.”
Furthermore, in verse 27, the Kingdom Gospel is called the “whole purpose of God.” Paul did not abandon his wholehearted attachment to the Gospel of the Kingdom (I Cor. 9:23). In Acts 28:23 Paul is in Rome gathering the Jews. “And he expounded the matter to them from morning till evening, testifying to the Kingdom of God and trying to convince them about Jesus both from the law of Moses and from the prophets.”
What we see after the ascension of Christ Jesus is the addition of the DBR, but never to the exclusion of the Kingdom of God. Paul preached to the Jews the Kingdom of God; they rejected it. Therefore, “this salvation of God” was then offered to the Gentiles.”  “This salvation of God” is the same as the Gospel of the Kingdom, which is seen in verse 30, 31:
“And he stayed two full years in his own rented quarters and was welcoming all who came to him, preaching the Kingdom of God and teaching concerning the Lord Jesus Christ with all openness, unhindered.” “The Good News about the Kingdom of God was Paul’s message for both Jews and Gentiles.”  This means it is also our Good News. Galatians 3:29 tells us that if we belong to Christ then we are Abraham’s descendents, and heirs to the same promises made to Abraham, i.e. the Kingdom of God.
This “two-pronged” Gospel was also preached by Philip in Acts: “But when they believed Philip preaching the good news about the Kingdom of God and the name of Jesus Christ, they were being baptized, men and women alike” (Acts 8:12). Water baptism, the outward sign of entrance into the Christian Church, did not take place simply after they had “accepted Jesus into their heart.” Rather it was only after they believed the Gospel of the Kingdom of God and in Jesus as Messiah and King of that Kingdom and now Lord of their lives, that they could be considered Christians. Does it worry us that today’s Christianity sounds nothing like the early Church? I think it should.
The Kingdom of God Message was one that the Jews understood well. It began with the promises made to Abraham (Gen. 12:1-3) when the land was promised to him and his descendents, who include now all those who are Christ’s. The promises were built upon through the Davidic Covenant. David is promised an heir to rule on his throne forever:
“When your days are complete and you lie down with your fathers, I will raise up your descendant after you, who will come forth from you, and I will establish his Kingdom. He shall build a house for My name, and I will establish the throne of his Kingdom forever. I will be a father to him and he will be a son to Me; when he commits iniquity, I will correct him with the rod of men and the strokes of the sons of men, but My lovingkindness shall not depart from him, as I took it away from Saul, whom I removed from before you. Your house and your kingdom shall endure before Me forever; your throne shall be established forever” (II Sam. 7:12-16).
A Messiah had been promised — a King over God’s Kingdom. God would give David a royal house, kingdom and throne forever. Clearly this hasn’t happened yet, and we are now awaiting the Second Coming of our Lord Christ Jesus to finally establish this promised Kingdom. Jesus is that heir of David. He will return to be King over the whole earth (Ps. 2:8). He will resurrect the faithful to reign with him in righteousness. Eventually a New Jerusalem is going to come down out of heaven and God will dwell with His people on the earth. There will be no more war, suffering or death. God will in fact wipe away all tears from His people’s eyes (Rev. 21:2-4). The followers of Jesus will help him rule the world and the wicked will be destroyed (Rev. 2:26; I Cor. 6:2; Dan. 7:27; Rev. 5:10).
The Jews knew the teachings of the prophets. They were waiting for the time when they would inherit the land. They were expecting the golden age.
“And behold, with the clouds of heaven one like a Son of Man was coming, and he came up to the Ancient of Days and was presented before Him. And to him was given dominion, glory and a kingdom, that all the peoples, nations and men of every language might serve him. His dominion is an everlasting dominion which will not pass away; and his kingdom is one which will not be destroyed…But the saints of the Highest One will receive the kingdom and possess the kingdom forever, for all ages to come” (Dan. 7:13, 14, 18).
This is the Kingdom of God as the Jews understood it. They were not confused in the slightest by Jesus saying, “The meek shall inherit the earth” (Matt. 5:5) or by Jesus’ model prayer, “Thy kingdom come; thy will be done on earth as it is in heaven” (Matt. 6:10). That is exactly what they were waiting for! What they did not understand was that the Messiah had to suffer before he could reign (Isa. Chaps. 52, 53). Tragically they rejected the king they had been waiting for. Luke 1:33 tells us how intimately connected Jesus was to the prophecies of the Hebrew Bible. “And he will reign over the house of Jacob forever” (2 Sam. 7:13, 16; Ps. 89:36, 37; Dan. 2:44; 7:14, 18, 27; Matt. 28:18), “and his kingdom will have no end.”
Jesus Christ died for the Kingdom so that you and I could enter it.
 F.C. Grant, The Gospel of the Kingdom, Biblical World 50 (1917), pp. 121-191.
 George E. Ladd, Crucial Questions about the Kingdom of God, Grand Rapids: Eerdmans, 1952, p. 173.
 Anthony F. Buzzard, Our Fathers Who Aren’t in Heaven, Restoration Fellowship, 1999, p. 201.
 George E. Ladd, The Gospel of the Kingdom, Grand Rapids: Eerdmans, 1959, p. 127.
 Ibid., p. 127.
The above post was taken from: Why One Half Is Not Enough