Two Treatises of Government by John Locke serve in many ways to refute the authoritarianism of Hobbes' Leviathan and the alliance of throne and altar that underlay much of the traditional relationship between the papacy and medieval monarchies, a belief system underpinning the notion of the divine right of kings as part of a hierarchy of being stretching downwards from God and angels through kings and nobles through the lesser human orders to animals and finally inanimate beings.
For Locke, governments rule with the consent of the governed, and it is this consent, rather than heredity or divine appointment that give them legitimacy. The consent of free people allows governments to make laws that protect the rights of all people and are enforced as much by common consent and agreement as by force. In other words, the reason people don't steal or murder is not that there are police on every corner, but rather than most people believe these acts are wrong and will cooperate with the government in reporting and enforcing the laws.
Another major point Locke makes is one of omission; religion is not discussed as an integral part of government but appears independent of political systems.