Thomas Jefferson opened his Declaration of Independence with a paragraph explaining its purpose:
“When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.”
Jefferson asserts that events have made it “necessary” to sever our political ties with Britain. This statement almost carries the ring of determinism. Events have forced Americans into this action. They can envision no other way to preserve their natural liberties than to assume “the separate and equal station” of an independent country.
Interestingly, Jefferson seems to suggest that the British colonists of North America do not become a separate "people" through establishing their independence, but rather already are a separate "people." And it is unnatural through political bands for one separate people to live in subjection to another. By declaring independence, the Americans assume the right to independence and sovereignty to which they are entitle by the Law of Nature and to Nature's God.
The role of the Law of Nature are problematic. Although the Law of Nature has a long pedigree, like many subjects of philosophical exploration, ambiguity and vagueness abounds. And Jefferson did not elaborate. In general, anything subsumed under the Law of Nature derives from human nature. And in most versions of natural law, God created our human nature. It is human nature for a "people" who possess a self-conscious identity as a "people" to establish the "separate and equal station" for their self preservation and happiness.
A brief note on Jefferson's religion. He grew up in the Anglican Church but certainly by adulthood became unorthodox in his faith. He was not a deist in the strict sense of the word. He believed that a supreme being not only created the world, but also acts upon it. He is best described as a Unitarian. Jefferson believed that the spread of education would retard the growth of orthodox Christian denominations, which he called "fanatical" as would the spread of Unitarianism. He believed that Unitarianism "will, ere long, be the religion of the majority from north to south, I have no doubt."
Jefferson asserts that a decent respect for the opinions or judgments of mankind requires that we state the causes that have forced or , his words, impelled, the decision for independence. He probably had three audiences in mind. First, the Declaration addressed other Americans. At the Continental Congress, nearly a month passed before a delegates reached a consensus on declaring independence. Moreover, John Adams believed that only about one-third of Americans fully supported the the movement for independence. The remaining holdouts were undecided or loyalists to the British crown. Second, the Declaration addressed the British public. Many British citizens wondered why subjects to the freest government in the world rebelled against it. Finally, the Declaration addressed foreign leaders. The Americans needed financial and material support from foreign countries in order to win independence. No foreign power cared during the years that the colonists asserted their ancient rights as British citizens. Once America made it clear to seek independence, other powers found it in their interest to encourage the break up the British Empire.