The kingdom of God is the rule of God; his reign established under the kingship of his Son, Jesus Christ. His reign produces the rule of God in our lives: righteousness, peace and joy in the Holy Spirit (Romans 14:17).
The Kingdom is the sphere in which the reign of God is experienced. His subjects are the people who enter the kingdom through repentance and faith in Jesus Christ, and who live under his lordship, governed by him in the power of the Holy Spirit (Matthew 4:23, 3:2, 18:3, John 3:5-8). These subjects of the kingdom constitute the church; they are the kingdom community. At Pentecost all who received Jesus as Lord were baptised and added to ‘their number’ (Acts 2:41).
It is impossible to be in the kingdom of God without being part of the church.
The church is the instrument of the kingdom. It displays in this present age the life of the ‘age to come’: the life and order of the end time kingdom of God. Acts 2:42-47 gives us a model of such a community; even though it was imperfect they affected the whole of the known world with the gospel of the kingdom.
While there is an inseparable relationship between the kingdom and the church, they are not the same. The kingdom is God’s reign and the realm in which his reign is experienced. The church comprises those who are living under that reign. The kingdom creates the church, works through the church, and is proclaimed in the world by the church.