The Kingdom of Light and of God is the Kingdom where God the Father rules with His Son and His Holy Spirit. In the Kingdom of Light and of God, you get God's people, angels, archangels, cherubim and seraphim, and all beings who are subject to God and are under His Command. God is Light, and in Him is no darkness at all, this is why His Kingdom is the Kingdom of Light, as opposed to the kingdom of darkness which is satan's. The Kingdom of God is not all about the Kingdom of Heaven. The Kingdom of Light and of God refers to God's Authority and Rulership throughout the entire universe - and this includes the universe of Heaven, though Heaven itself is not a physical plane but a spiritual plane.