Jesus came preaching the gospel of the kingdom. The word kingdom is translated from the Greek word basileia, which means rule, dominion, power and sovereignty. God's kingdom is the sovereign rule of God. You enter the kingdom of God, when you repent and believe the gospel of Christ (Mark 1:15).
Jesus said, For indeed, the kingdom of God is within you (Luke 17:21). The Holy Spirit brings the kingdom within every believer. You become the dwelling place of the Holy Spirit. The righteousness of God is accounted to you by grace through faith in Christ. You have peace with God and the joy of your salvation. For the kingdom of God is not eating and drinking, but righteousness and peace and joy in the Holy Spirit (Romans 14:17).
Jesus said to Nicodemus, You must be born again (John 3:5). To be born again is a work of the Holy Spirit, through the gospel of the kingdom (John 3:8). You are born again, when you believe on the Lord Jesus Christ (1 John 5:1). You have entered the kingdom of God (John 3:5).
The kingdom is within you through the Holy Spirit. Yet, God's kingdom shall come in all of its fulness at the second coming of Christ. Then comes the end, when He delivers the kingdom to God the Father, when He puts an end to all rule and all authority and power. For He must reign till He has put all enemies under His feet (1 Corinthians 15:24-25).
