Jesus' message about the Kingdom of God may be unfamiliar and unbelievable to many Christians today. But the gospel - the good news - of the Kingdom was a core belief and teaching of the first Christians. Here are a few of the verses about the preaching of the Kingdom of God:
Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God (Mark 1:14)
And it came to pass afterward, that he went throughout every city and village, preaching and shewing the glad tidings of the kingdom of God: and the twelve [were] with him (Luke 8:1)
…he [Jesus] showed himself alive after his passion [death and resurrection] by many infallible proofs, being seen of them [the believers] forty days, and speaking of the things pertaining to the kingdom of God (Acts 1:3)
But when they [some Samaritans] believed Philip preaching the things concerning the kingdom of God, and the name of Jesus Christ, they were baptized, both men and women (Acts 8:12)
And he [the apostle Paul] went into the synagogue, and spake boldly for the space of three months, disputing and persuading the things concerning the kingdom of God (Acts 19:8)
And now, behold, I know that ye all, among whom I [Paul] have gone preaching the kingdom of God, shall see my face no more. (Acts 20:25)
…there came many to him into his [Paul's] lodging; to whom he expounded and testified the kingdom of God, persuading them concerning Jesus, both out of the law of Moses, and out of the prophets, from morning till evening. (Acts 28:23)
And Paul dwelt two whole years in his own hired house, and received all that came in unto him, Preaching the kingdom of God, and teaching those things which concern the Lord Jesus Christ, with all confidence, no man forbidding him. (Acts 28:30,31)
These verses clearly show how important the Kingdom of God was to the early Christians. But over time, as professing Christianity changed into the forms familiar to us today, the gospel of the Kingdom was put aside. The historian Edward Gibbon, in The Decline and Fall of the Roman Empire, described the early believers and the later suppression of the gospel of the Kingdom. The early Christians believed...
... that Christ, with the triumphant band of saints and the elect who had escaped death, or who had been miraculously revived, would reign upon the earth till the time appointed for the last and general resurrection…. The assurance of such a Millennium was carefully inculcated by a succession of fathers from Justin Martyr and Iraneus, who conversed with the immediate disciples of the apostles, down to Lactantius, who was a preceptor to the son of Constantine. Though it might not be universally received, it appears to have been the reigning sentiment of the orthodox believers; and it seems so well adapted to the desires and apprehensions of mankind, that it must have contributed in a very considerable degree to the to the progress of the Christian faith. But when the edifice of the church was almost completed, the temporary support was laid aside. The doctrine of Christ’s reign upon the earth was at first treated as a profound allegory, was considered by degrees as a doubtful and useless opinion, and was at length rejected as the absurd invention of heresy and fanaticism. A mysterious prophecy [referring to the Revelation], which still forms a part of the sacred canon, but which was thought to favour the exploded sentiment, has very narrowly escaped the proscription [official condemnation] of the church. (Edward Gibbon, The Decline and Fall of the Roman Empire, Chapter XV, Section II)
Today most Christians are unfamiliar with the gospel of the Kingdom. The gospel has been replaced by a variety of other messages. Some teach an emotional message about "giving your heart" to Jesus, the messenger of the gospel. Others preach salvation through sacraments and ceremonies, and even teach that their religious organization is the Kingdom of God. Over the centuries the gospel of the coming Kingdom of God has nearly been lost. And God's expectations of us - and promises to us - have been seriously misunderstood.