The 'Kingdom of Heaven' does not represent a spatial concept alone. However, is the Kingdom of Heaven truly only 'within our hearts'? It is likely that quite a few people would answer yes to this question.
Jesus gives the answer. “If I cast out demons by the Spirit of God, the kingdom of God has come to you.” (Matthew 12:28) What is important here is that the kingdom of God has come not only ‘in your hearts’ but ‘to you’ (in ancient Greek, ‘on you’ or ‘around you’). Jesus also says, “The kingdom of God is within you” (Luke 17:21). This statement carries no mere temporal or spatial significance. It signifies that a completely new era has fully opened, transcending time and space. With the appearance of Jesus, a new era—the era of salvation, that is, the Kingdom of God—has begun to sprout in earnest. “Then Jesus said to him, ‘Get behind me, Satan! For it is written: “Worship the Lord your God and serve him only”. Then the devil left him, and angels came and ministered to him.” (Matthew 4:10-11) Those who were groaning in the clutches of the devil are liberated, healed, and come to see the light. When the seventy-two disciples whom Jesus had sent returned and reported the progress of their work, He Himself testified: “I saw Satan fall like lightning from heaven.” (Luke 10:18) In this way, with the appearance of Jesus, the age of Satan fades away. “Jesus called the twelve disciples to him and gave them authority over unclean spirits to cast them out and to heal all the sick and infirm.” (Matthew 10:1) In the New Testament, "unclean spirit" is a term that can be used as a synonym for "evil spirit". Jesus' disciples are granted not only the authority to cast out evil spirits but also to heal the sick and infirm. “So they went out and preached repentance. And they cast out many demons and anointed many sick with oil and healed them.” (Mark 6:12-13) Instead of “I by the Spirit of God” (Matthew 12:28), Luke conveys in a parallel passage, “if I cast out demons by the finger of God” (Luke 11:20). This statement brings to mind the story of Pharaoh’s sorcerers who denied Moses’ miracles.Pharaoh’s sorcerers, having experienced the power of the Lord God performing miracles through the hands of Moses, unintentionally confess their faith(?). “This is the work of the finger of God”. They, too, had no choice but to acknowledge that such amazing miracles are something only God can do, and that they are His own work accomplished by His finger, that is, by Himself.
The Apostle Paul gives us guidelines on how we, who have been invited to the Kingdom of God, should live. “The Kingdom of God is not eating and drinking, but righteousness and peace in the Holy Spirit… So let us devote ourselves to things that contribute to peace and to the growth of one another.” (Romans 14:17-19)
