The thoughts of kings and kingdoms are foreign to our 21st-century mindset. The very mention of them brings to mind fairy tales and medieval legends. Our view of a kingdom is romanticized and very separated from our day-to-day life.
But in the ancient world, the king was supreme. His word was absolute and uncontested. The citizens would thrive under a good king or chafe under a bad king, who would rule until his death or defeat (by a more powerful king).
When God established the nation of Israel and called them to be His own people, He set up a government where God Himself would rule as their perfect king (see Exodus-Deuteronomy). But the people rejected God’s rule and demanded a king of their own (1 Samuel 8:4-9). Throughout the rest of Old Testament History, the fortunes of God’s people rose and fell based on the character of their kings.
But God had greater plans for His people. Every book of the Old Testament promised that a great king would come. He would save mankind from the curse of sin, and lead Israel in a victorious, perfect kingdom. He was the Promised One, the Anointed One, or in Hebrew, The Messiah (see here).
The Old Testament prophets also wrote about His kingdom. Daniel saw the empires of mankind destroyed by the kingdom of God that would never end (Daniel 2:44, 7:27, see here). Isaiah saw the kingdom of God as a kingdom of peace and safety, where the wolf would dwell with the lamb (Isaiah 11).
This kingdom of God was a real promise that Jews anticipated. As they were dominated by the world empires — Babylon, Persia, Greece, and Rome — they looked forward to the day when their Messiah would come and free them, restoring peace to the world. When John the Baptist came announcing that the kingdom of heaven was at hand, the people came by the thousands. They were ready to be free!
Jesus followed John with the same message: the kingdom of heaven was at hand1. But Jesus never came with military force. He never drove out the Romans, nor did He oppose any conquering army. He had no political power. Yet Jesus spent most of His ministry teaching about His kingdom. So what is His kingdom? What is the kingdom of heaven?