The second part, less often referenced, lays out the reasoning for why we were seeking independence, a reasoning that included a long list of King George III's grievances.
"Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security. ... The history of the present King of Great Britain is a history of repeated injuries and usurpations, all having in direct object the establishment of an absolute Tyranny over these States."
A detailed list of grievances for all the world to view followed.
Our founders concluded the document with the pledge to each other, and an invocation of God. "And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor."
Knowing that their declaration would be seen as an act of treason by the king, the signers also knew that, if they were not successful, they would risk losing their lives.
This document declared us free, outlined the foundational understanding of our rights, from whom they came, and our responsibilities to maintain them.
These days, of ongoing budget deficits, increasing regulation and taxation, retaining our independence might be more challenging than the original declaration.