Jesus said in Luke 17:20, that the Kingdom of God, is in us. The Kingdom of God, is manifested in this world, through us, but it is first of all, in us as Christians.
In Matthew 12:28, Jesus also said, that driving out demons from people, in his name, is also part of the Kingdom of God, and that is one of the manifestations, of the Kingdom of God. You see, it is not just about a good Christian character. A good Christian character, and for us to love God and people, is the most important for us, as Christians, but that is not enough, to demolish and overcome, the things done, by the Kingdom of darkness.
Jesus said that by the Holy Spirit of God, he is driving out demons, in Matthew 12:28. The Bible also says in the book of Acts, that the Son of God, Jesus Christ, came on this earth, to destroy the works of the devil. And he destroyed them, indeed, glory and thanks to our Lord Jesus Christ for that! We are called kings and priests in the New Testament. What type of kings and priest we are, if we do not display the Kingdom of God in our life?
Jesus also said, in Luke 8:10, that the secrets of the Kingdom of God, have been given to us Christians, to know and understand. You see, if we are Christians, those spiritual matters and revelations about the things of God, and how the Kingdom of God operates in our life, as Christians, have been given for us to know, and apply in our life, for the glory of God, and for establishing his Kingdom, on earth, through us.
If you do not understand anything you read from the Word of God, ask the Holy Spirit to show you, what that means, because the secrets of things from heaven, from God, have been given for you to know. And we have the mind of Christ, as the Bible says.
In John 3:5, Jesus said, that no one can enter the Kingdom of God, unless he is born again. But once we are born again from the Holy Spirit, we have the Kingdom of God, in us. The darkness in this world, is getting more and more obvious, but the light of the Kingdom of God in us, is surely getting brighter and brighter, because, there is no way, that God will allow, darkness to stay and rule in this world, forever, because the Light shines in the face of darkness, and the darkness has to disappear.
The light of the Kingdom of God, will always expel and overcome darkness.