Even before Christ's ministry began, the prophet John prepared the way for Jesus' central message: “The kingdom of God is at hand!” Ironically, the idea of a “Kingdom of God” was not new. It is the Old Testament's core idea, for Israel was God's Kingdom on earth, the nation over which God ruled directly. John the Baptist's cry in the wilderness signified a change in understanding that Jesus would explain throughout His ministry and inaugurate through His church.

The Greek word underlying “kingdom” is basileia (Strong's #932), which means “a kingdom” or “a realm,” that is, the area or country that a king governs. However, it can also denote “royal or kingly power, authority, dominion,” a king's reign or rule, or even his royal dignity. So, it not only speaks of a king's geographical domain, but it also refers to his authority and right to govern—in other words, his sovereignty.

The idea of the Kingdom of God, then, is not limited to a specific place or even a particular time. It is the reign or rule of God wherever and whenever it is in effect. Thus, the apostle Paul can write in Colossians 1:13 that God's converted people have already been “conveyed into the kingdom of the Son of His love.” Jesus' ministry proclaimed the good news of the coming of that Kingdom, but not just its culmination in the dim mists of the future. He announced that the Father was opening an entrance into that Kingdom immediately for a chosen few (John 1:12-13; 6:35-40; see Matthew 22:1-14). Those who responded positively to His call would come under Christ's rule in this life (Luke 12:32; John 4:23-24; Acts 2:39; I Thessalonians 2:12; Hebrews 12:28).