What purpose did the introduction to the declaration of independence service

The Declaration of Independence was a new and radical way to:
a) Start a country.
b) Establish that country with very definite principles about the relationship between government and the people. 

The purpose of the introduction to the declaration of independence service was:
"It indicated why independence was necessary".

 According to the declaration of independence, Government has the power to protect natural rights, but people can change their government if it fails to do so.

The second , larger puritan colony of massachusetts bay was conceived as a "city upon a hill". but it also struggled with internal turmoil like the salem witch trials and external conflicts like king philip's (metacom's) war.