With our finite minds there is not a whole lot we can say about the kingdom. Jesus doesn't describe it in detail, but one thing we can say with an air of certainty, it has something to do with love.
The scribe asked Jesus, "What is the great commandment?"
Jesus answered, "You shall love the Lord your God with all your heart, soul, mind, and strength and your neighbor as yourself."
Wherever God is, there is love. Wherever love is, there is God. The kingdom has something to do with love. Paul says, "There remains these three: faith, hope, and love. But the greatest of these is love." In other words, if we are a citizen of the kingdom of God, it will show by the way we love one another.
We cannot hold on to our resentment, our anger, our prejudice, and our bitterness, and claim citizenship in God's kingdom. The Kingdom is centered on love for people. We would all be so much healthier and happier if we lived by that principle.
I remember a story of a girl who was told by her mother to take flowers to a shut-in who lived down the street. She did so and it was a marvelous visit. When she came back her mother said, "Smell your hands." She did and she was surprised to discover that the fragrance of the flowers still lingered on her hands. Her wise mother said to her, "Kindness always leaves a sweet fragrance."
The kingdom of God is like that too.