The Divine Right of Kings Theory, as the name implies, holds that a monarch rules by divine right, that God has selected a particular ruler as the divine representative on Earth. In many ancient cultures, like Egypt, a proto-type of this theory is seen in the god-king where the civil ruler is an embodiment of God. But once monotheism, exemplified in Judaism, Christianity, and Islam was firmly established as the main religious paradigm in the West, a sharper separation between God and king became necessary. The famous Christian theologian St. Augustine of Hippo (CE 354-430) gave the first systematic articulation of a political theory that distinguished between God and king in his City of God (completed in 426). Though Theology, not Axiology, was St. Augustine's main concern, we find in his work a theological justification for human political institutions. Building off of the claim of St. Paul that all earthly governments are established by, and are under the providential control of God (Romans 13:1), kings and emperors serve the will of God in their reign. That is, God appoints earthly rulers for whatsoever reasons God finds compelling. And, these reasons need not be evident to us if we have faith that God is the supreme ruler of the Universe.
During the Medieval Period (c. CE 650-1350) the idea that kings rule as God's representatives on earth was expanded and institutionalized throughout Europe. A king could only be legitimate if recognized by the Church, and in return the crown would support the clergy with lands and tithes/taxes. Political power was thus divided evenly between the religious and secular aristocracies while the vast majority of the population was kept subject by the twin fears of health and Hell. The powers of both the Church and the crown were absolute in this political system; the pope and the monarch were considered to be accountable only to God, not to the people they ruled. If one was fortunate enough to be born into the aristocracy (high ranking members of the clergy were almost always members of the aristocratic class), then life would be good--by Medieval standards.
This is the political theory Hobbes will reject, wholesale. Though Hobbes remains a Christian, he rejects the political theory derived from St. Paul and St. Augustine. So, if monarchies are not directly established by God, whence cometh government? Hobbes will argue that government arises out of the natural condition of humanity, Egoism. Persons, if left to their own devices and without supervening authority, will always tend toward their own satisfaction. That is, Nature (i.e., God) has built into us a desire to preserve our own life, and given us the liberty and ability to accomplish that end. The problem, is that we are not alone. We must compete for survival and that competition creates an environment that is undesirable. Thus, we must form a compact for mutual cooperation and protection which enables us to establish a more tolerable existence. That compact is the foundation of all government.
For Hobbes, Morality (and Justice) is a by product of Law; where there is no law there can be neither morality nor justice. It is in our best interest, therefore, to discover or invent law.
Because of Nature, our desire is for a long and peaceful life. This can only be accomplished in a community where our competing self-interests are controlled by law. Since such institutions do not exist naturally, we must create such communities (i.e., states) by trading liberty for safety.