The kingdom of God is a big club that only nice and good people can belong to. It's like a fancy and special club where everyone is happy, helpful and kind to each other.
God is like the leader of this club and he only lets in people who follow his rules and are kind to others. The club is not just a place, it's also a feeling that you get when you follow these rules and do good things.
God wants everyone to be part of this club so that they can be happy and feel loved. However, it's not always easy to follow the rules and be nice all the time. But if you try your best and do good things, you can be part of this special club too!