The Kingdom of God may seem elusive due to the numerous analogies Jesus utilized to speak of this heavenly domain. However, truth is often hidden in simplicity.
One could say that the Kingdom of God is in heaven.
But it was never to remain confined to heaven for Jesus taught us to pray that His Kingdom come and His will be done on earth as it is in heaven. Thus, the Kingdom is not waiting for the saints to come to their eternal glory. It is an eternal glory presently available to change the earth to its nature.
The Kingdom of God can be found for it is righteousness, peace, and joy in the Holy Spirit
Paul tells us precisely where the Kingdom of God can be found for it is righteousness, peace, and joy in the Holy Spirit. Thus, the Kingdom of God is in the Holy Spirit.
Jesus is the King of the Kingdom making the Kingdom of God an extension of who He is. Just the same, He left us the Holy Spirit so that we could access the Kingdom of God by His Spirit which leads us into all truth.
Christians are on a great quest to issue the Kingdom of God upon the earth thereby making earth look like heaven wherever we release the Holy Spirit. When we partner with the Holy Spirit we bring the glory of God to light. The sick are healed, the dead are raised, peace is released to change an atmosphere, joy is present, and righteousness reigns.
Kingdom of God affect the physical world the Kingdom of God
To the degree that these aspects of the Kingdom of God affect the physical world the Kingdom of God is made visible. This happens when the Kingdom is demonstrated in art, music, law, economics, financial planning, family life, the marketplace, etc. Every place the wisdom and life of heaven are demonstrated illustrates the Kingdom of God.
Since Christians are filled with the Holy Spirit, the Kingdom of God, the domain of Jesus, is inside of us. When we live in accordance with that eternal life we carry the Kingdom of God. When we live that out on the earth, the Kingdom is now also on the earth.
The Kingdom of God can be experienced in a location
Therefore, the Kingdom of God can be experienced in a location, but it is more than its location. It is the outworking of the realm of God, the domain of God, and it is seen where He is present.
Imagine such a world where Jesus is King and the domain of all of nature is restored to the glory of a Kingdom of God, a new Eden and a new Jerusalem. The full power of such a Kingdom is on the inside of every Christian filled with the Holy Spirit. Once we know we are so equipped, we are ready to utilize that power for His glory to a watching world.