The kingdom of God is only visible in the body of Christ.
For the kingdom of God is not meat and drink; but righteousness, and peace, and joy in the Holy Ghost (Rom.14:17).
The beatitudes in Matthew 5 are the attributes of the people who have entered in the kingdom.
It is doing what Christ would do. Preaching the gospel is not an option. There's no place for Apostolic spectators. If Jesus died for all men, then all men should hear the gospel. The church is not a museum, not a parade of talents, not a place for selfish ambition.
The 4 How's (Rom. 10:14-15):
- How then shall they call on him in whom they have not believed?
- How shall they believe in him of whom they have not heard?
- How shall they hear without a preacher?
- How shall they preach, except they be sent?