The Kingdom of God (and its related form Kingdom of Heaven in the Gospel of Matthew) is one of the key elements of the teachings of Jesus in the New Testament. Drawing on Old Testament teachings, the Christian characterization of the relationship between God and humanity inherently involves the notion of the Kingship of God. The Old Testament refers to "God the Judge of all" and the notion that all humans will eventually "be judged" is an essential element of Christian teachings. Building on a number of New Testament passages, the Nicene Creed indicates that the task of judgment is assigned to Jesus.
–Wikipedia