It is so very important to understand what Jesus and the New Testament authors mean when they refer to the kingdom.
It is understandable why so many Christians imagine our traditional understanding of "Heaven" when they hear the term "the Kingdom of Heaven". But the Kingdom, as used in scripture, is not even a place. As you will see shortly, the Kingdom of Heaven (or God) includes Heaven, but it is not Heaven.
So what is it? Don McLaughlin taught me that every time I read the word "kingdom" in the New Testament, I would do better to read it as "kingship". Why?
Because the Kingdom of God is present wherever God's will is being done.
In the Lord's prayer, Jesus puts two requests side by side: "Your kingdom come, your will be done, on earth as it is in heaven." (Matt. 6:10) The second phrase actually defines the first. In other words, the Kingdom is present wherever Godís will and rule reign.
Now add Paul's statement in Romans 14:17 and we can actually understand what living under Godís rule would feel like! He says, "The Kingdom is a matter of peace, joy, and righteousness in the Holy Spirit." (Romans 14:17) In other words, when you believe, receive, and surrender to the will of God, you will experience the Kingdom of God within you as an experience of peace, joy, and righteousness.
This makes sense of what Jesus says in Luke 17:21 - "The Kingdom of God is within you."
Today, we talk about this Kingdom matter of joy, and how to let the Holy Spirit keep it alive within us no matter where we are or what is happening.