Jesus launched his public ministry by proclaiming, "The Kingdom of God is at hand." What does that mean? Where is the Kingdom of God?
Of course, ultimately the Kingdom of God is heaven. But it must accessible now, or why else would He say it was "at hand"?
The Kingdom of God is not a place. It is a way of life.
The Kingdom exists wherever Christ reigns. It exists in the heart of every one who accepts Him as King. And it is the job of each of His subjects to extend that Kingdom.
The first step is not to hide the fact that one is a member of His Kingdom. Rather, you start by bringing the Kingdom with you wherever you go. It means being what Paul told us we are to be: "ambassadors for Christ" (2 Cor 5:20). We represent Him wherever we go.
And then, we are to build little outposts of the Kingdom wherever we can. It's a kind of colonizing that brings only goodness and love to the natives.
Our biggest opportunity lies where we reign. For most of us, this would be our own homes, but whether you also run a corporation or merely share a room with a sibling or roommate, everyone has some say over one's own space.
As ambassadors, we must each establish an embassy of the Kingdom. An embassy, remember, is a small station of its home country, lying in a foreign land. When you enter an embassy, you enter that country, even though it's surrounded by another nation. It's up to me to transform my domain into a microcosm of the Kingdom.
The Kingdom is as close as you make it.