I have noticed a difficulty in the terminology; “Kingdom of God.” In many recent conversations I have had I’ve noticed that there is a tendency within popular Christianity to distinguish too much of a dichotomy between what is God’s Kingdom and what is not. This may be closely related to the accepted dichotomy between what is “Spiritual” and what is “Secular.” We’ve, somehow distinguished a difference between the world and God’s world. In reality this world, all we see and don’t see, belongs to God and is under His rule.
We often have tried to set the Church apart. This is a noble aspiration in light of God’s calling which St. Paul calls being “holy” (1Thes. 4:3) or being “set apart” (1 Cor. 6:11). But we have decided to do it by a sort of seclusion. We have created a barrier between ourselves, the Church, and “the world,” which is really just all the things we have decided to banish from within our circle. While being set apart is about a certain quality of life we have re-defined it into form of materialism. Not necessarily the sort of materialism that collects things and adds to its wealth but the kind that disallows material and spiritual to overlap. We have decided that society, culture, politics, and general civilization are one thing and the Kingdom of God is another. We’ve decided that these things are “secular” and God’s Kingdom is “spiritual.” Reality is that all these things are part of the Kingdom of God. Due to the nature of God His Kingdom must possess all things, seen and unseen. All things are to be embraced within His kingdom. This certainly does not mean they will keep their form for God’s rule demands change; submission from chaos to harmony. There is not a kingdom of God and a kingdom of this world. There is only the kingdom of God and everything else is waiting to be clinched within the grasp of its fingers. The Eschaton will not be the destruction of one kingdom over another. It will be the warm embrace of a kingdom bringing all things within the reign of God.
The Kingdom of God is not conquest. It is not about zones and boundaries. The Kingdom of God is a Kingdom of the hearts of all people. It transcends territory and dichotomy. This kingdom is holistic and it blows all of our definitions and restrictions out of the water for it’s King does not live in buildings made by human hands (Acts 17:24). Our task is not to decide what is and isn’t of the Kingdom. Ours is the task of bringing all things under the reign of God. This spans through, culture, through our political agendas, through how we care for the environment, and through how we deal the lady at the checkout counter. We have an all encompassing mission.
“If what we mean [by the Kingdom of God] is a particular space or sector, we talk about ‘the realm of the good’ and ‘the realm of evil,’ and about ‘the two kingdoms,’ one spiritual and the other secular. But if the kingdom has to do with God, there cannot be two or more kingdoms, because God is one and there is no one besides him.” 
 Jurgen Moltmann, Jesus Christ for Today’s World (Minneapolis, Fortress Press, 1994) 8.