...These comparisons between the Kingdom of Christ, the regnum Christi, and the kingdoms of the world, the regna mundi, help to define the essentially "spiritual” nature of Christ’s Kingdom. They (as we shall see later) provide a base for the development of church=civil government relationships. These distinctions or differences do not necessitate separation. If some could misread these comparisons to mean “keep them separate because they are different”, then this doctrine of Christ’s Kingdom and Kingship would say “bring them together because they are different”. Christ’s spiritual Kingdom can and does include things that are physical and mundane. For example, when God converts a soul so that he becomes a spiritual person, He does not cease to have a physical body. So long as God maintains a visible, witnessing Church on earth, as one form of the Kingdom of Christ, it will involve the physical being part of the spiritual kingdom. Since Christ has told us He has “all power” and has been made head over “all things”, then we can know that in His (spiritual) Kingdom, there will be those things that are, in and of themselves, physical.
Even money, “dedicated” to the Lord becomes an important factor in Christ’s development of His spiritual kingdom. Anything which can, or can be made to have, a spiritual purpose can be seen to be part of Christ’s spiritual Kingdom. When Christ said, “My kingdom is not of this world”, He had no more thought of excluding physical things and political and social=family relationships than when He said to His disciples “ye are not of this world” (the Greek phrase is identical).
When we ask on behalf of the Christian businessman or the man in civil government or the father in a family, “but how can these physical things which occupy so much of my time ever be part of Christ’s spiritual Kingdom?”, we must know the question is caused by the statements in Scripture and so God will answer it.
The answer is to be found in the fact that whatever is connected with Christ’s Kingdom is connected in some way to Christ’s spiritual objectives–objectives that live beyond the time and space restraints in our world. It is the ultimate objective which determines the nature of a thing. When the businessman or man in government can see a direct relationship between his daily work and Jesus’ reason for dying for him on the Cross, then he will see how his physical job is part of Christ’s Spiritual Kingdom.