The kingdom is often limited to the hearts of the regenerate, heaven, or the eternal state. This virtually denies that the messianic kingdom has anything to do with this present earth. In contrast to this tendency, Scripture makes it abundantly clear that this earth, although not the source of the kingdom, is a part of the kingdom. Christ's messianic authority and reign extend over all of heaven and earth (Matt. 28:18), and He is in the process of subduing all of His enemies, whether in heaven or on earth (1 Cor. 15:25).
~ Keith A. Mathison