Christians believe a variety of things about the Kingdom of God.
Some think of the Kingdom simply as the place, called heaven, we will eventually go to when we die.
Others think of it as the final victory on earth where righteousness will rule and all other kingdoms will either be wiped out or else will be subservient to King Jesus. They believe there will be a final revival when people turn to God en masse.
Others still think the Kingdom is “out there somewhere”. God is not personal and we cannot have an intimate relationship with him. It’s like in Moses’ day, when God was removed and unapproachable, except by the elite or super spiritual.