The relationship between the colonists and England deteriorated quickly after conclusion of the French and Indian War. The motives behind seeking a new government were of the economic, political, and cultural variety.
The colonists were not happy with the fact that England was beginning to enforce its tax acts after the French and Indian War. This was damaging commerce and trade in the colonies. Some industries, like rum production as an example, could not survive if they were expected to pay the taxes on sugar and molasses. Throughout history, money has moved people to take drastic measures, and it was no different in colonial America.
The cultural motivation for a new government mostly centered around religion. Many colonists held deep convictions that there should be religious freedom. This is evident in the Bill of Rights as the separation of church and state is included in the First Amendment. The primacy of this doctrine in the new nation's Bill of Rights demonstrates how important it was to the colonists.
The political motive behind the Declaration of Independence is one of representation, of which the colonists had none in the English Parliament. The colonists felt that if they were going to pay taxes, they should have representation in the lawmaking body. This concept was a rallying cry throughout the Revolution: taxation without representation is tyranny.