What the Kingdom of God Is. In the simplest terms, the Kingdom of God is the rule of God. Thus, it can be said that wherever the Lord Jesus Christ reigns, there you have the Kingdom of God.This is true whether Jesus rules in an individual life or over a group of people.hat the Kingdom of God Is. In the simplest terms, the Kingdom of God is the rule of God. Thus, it can be said that wherever the Lord Jesus Christ reigns, there you have the Kingdom of God.