Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
by Richard Sutton
Freedom of, and from, religion is assured to Americans in the first amendment. The First amendment also provides important protection for the freedom of the people to speak, peaceably assemble, and to petition the government.
The founders were well aware of the effects of state sponsored religions due to their own experiences and understanding of history. Their conclusion became (not without some argument) that it is best that government not sponsor one religion and oppress all others. They knew from the example of Philadelphia that religious tolerance leads to greater prosperity and happiness.
They also had experience with the suppression of the Press, the right to peaceably assemble, and the right to petition government which is WHY these amendments were created - they didn't form out of thin air but were placed due to the history and experiences of the people that introduced them.
Most of them also did not want the government to decide what they would be allowed to believe. Do you? If you give government the power to control your neighbor you have also given it the power to control YOU.
It was a good idea then and it is a good idea now - the principles of the First Amendment are really quite timeless.
Additional resources for action and education:
People for the American way
A copy of the First amendment with comments and explanations:
A site targeted to helping teachers and advocates educate regarding the 1st amendment
The First Amendment Handbook (from the Reporters Committee for Freedom of the Press) this provides a detailed legal framework for working within the first amendment as a journalist, or blogger, or anything else.
For information regarding the right of political dissent and its status in the U.S.:
Is The United States Built on a Foundation of Christian Principles? - Kimberly Ruff
The Catharsis of the American Civil War: How the Near Division of the United States Served to Strengthen the Union - Kimberly Ruff
Protected by the First Amendment - Richard Sutton