“from the least of them to the greatest.” Under the New Covenant in Christ’s future kingdom there will still be a hierarchy among the people. Although it is unclear how this hierarchy will be established in the New Jerusalem and Everlasting Kingdom of Revelation 21 and 22, in the Millennial Kingdom of Christ it will certainly be based in large part upon what a person did for the Lord in their life on earth, and reigning with Christ in his earthly kingdom will be part of the reward that people receive for being faithful to God and Christ now.
Jesus’ apostles knew there would be different positions of authority in Christ’s kingdom, which is why Zebedee’s wife, the mother of James and John, came to Jesus and asked that her two sons sit next to Christ—one on the right and one on the left—when he reigns as king, and why the other apostles were angry at the request (Matt. 20:20-24; Mark 10:35-41).
Getting to reign with Christ in the future is just one reason that believers should be very serious about their walk with the Lord and serving him. The person who serves well will reign with Christ (2 Tim. 2:12), while if we ignore Christ or turn from him we may forfeit all our rewards in the Millennial Kingdom (1 Cor. 3:11-15; 2 Cor. 5:10; 2 Tim. 2:12).
[For more information on the future Millennial Kingdom on earth, see Appendix 3, “Christ’s Future Kingdom on Earth,” and also see commentary on Matt. 5:12; 6:1; 1 Cor. 9:26, 27. For more about rewards in the future Millennial Kingdom, see commentary on 2 Cor. 5:10, “good or worthless.” For a much more complete explanation of the Millennial Kingdom and rewards in the future, see John Schoenheit; The Christian’s Hope: The Anchor of the Soul].