Many professing evangelicals today believe the kingdom of God is strictly in the future, although there is no biblical foundation for that. This view robs the church of important teachings concerning the kingdom that are clearly set forth in the New Testament. In fact, the New Testament opens with John the Baptist's announcement of the kingdom: "Repent, for the kingdom of heaven is at hand" (Matt. 3:2). The Old Testament prophets spoke of the kingdom to come at some point in the future, but at the time of John the Baptist, it was about to burst onto the scene. It was "at hand." If we examine John's message carefully, we see that his announcement of the kingdom contained urgent warnings: "Even now the axe is laid to the root of the trees" (Matt. 3:10) and "His winnowing fork is in his hand" (Luke 3:17). Time was running out, and people were not ready.
Christ came on the scene just a short time later with the same message: "The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel" (Mark 1:15). However, there were differences between the behavior of John the Baptist and that of Jesus. John was an ascetic; he lived a life of radical self-denial. He ate locusts and wild honey, and dressed like the Old Testament prophets. Jesus, on the other hand, was accused of being "a glutton and a drunkard" (Matt. 11:19). He went to the wedding feast at Cana and ate at a banquet with tax collectors, which caused some of John's disciples to ask Him, "Why do we and the Pharisees fast, but your disciples do not fast?" (Matt. 9:14). Jesus replied, "Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from them, and then they will fast" (v. 15).
Another time the Pharisees asked Him when the kingdom of God would come, and Jesus replied, "Behold, the kingdom of God is in the midst of you" (Luke 17:21). The kingdom was in their midst because the King was there. On another occasion, He said, "But if it is by the finger of God that I cast out demons, then the kingdom of God has come upon you" (Luke 11:20).
So John came first with his warning of the radical nearness of the kingdom. Then Jesus came announcing the presence of the kingdom. This was followed by the acme of His redemptive work in the ascension, when He left earth to go to His coronation, where God declared Him King. As Jesus stood on the Mount of Olives, ready to depart, His disciples asked him, "Lord, will you at this time restore the kingdom to Israel?" (Acts 1:6). They had been waiting for Jesus to make His move, to drive out the Romans and establish the kingdom, but Jesus replied, "It is not for you to know times or seasons that the Father has fixed by his own authority. But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth" (vv. 7–8).
In answer to their question about the kingdom, Jesus gave the fundamental mission of the church. Men would be blind to His kingship, so His disciples were given the task of making it visible. The fundamental task of the church is to bear witness to the kingdom of God. Our King reigns now, so for us to put the kingdom of God entirely in the future is to miss one of the most significant points of the New Testament. Our King has come and has inaugurated the kingdom of God. The future aspect of the kingdom is its final consummation.
This excerpt is taken from Everyone's a Theologian by R.C. Sproul_._