Kingdom of heaven or kingdom of God means in the bible: They can be used with different meanings and combinations. The Church is generally considered the Kingdom of God. This is preparation for the larger kingdom, which can be described as the celestial kingdom or kingdom of Heaven. These terms are defined in DC 65 in this way. Sometimes, however, the term kingdom of heaven can be used to refer to the Church in Matthew. The true church is the way to heaven, and it is also the kingdom of heaven.
(in Bible Dictionary)