When I was in my formative years, it was taught in school (American History) that the pilgrims came to this country to escape religious persecution. I remember the puritans settled in Massachusetts and the New England area to better practice their beliefs. Throughout our early colonization, different religious groups came to America to escape the Church of England. The memories of the persecution they suffered while in England were passed down to generations of colonists until we finally separated from Great Britain and formed our own Union.
When The Continental Congress was convened to put together a new government in an experiment unprecedented in modern history to that time, it mulled over the question of religion and government. I may be wrong, but I was taught that the Continental Congress decided that religion was a personal issue, and that everyone was entitled to believe, or to not believe in a spiritual power, or God as some prefer, and that the state was not to interfere with those beliefs. They called it freedom of worship, or freedom of religion. At the same time, and in almost the same context, because of the myriad beliefs that people held, even in those times, our forefathers, in their infinite wisdom, also decided there should be a separation of church and state. Precisely because different people have different beliefs, the inclusion of religion in the political life of our country, would indubitably lead to differences of opinions and along with the very nature of politics, lead to such a difference of opinion, that the best way to reach a consensus between people of differing faiths, was to take religion out of the political equation; thus the separation of church and state.
Could you imagine the confusion in the House of Representatives if every bill introduced had to pass scrutiny of every representative's religion? True, at times members of the House and the Senate will let their religious views dictate the way they vote, but rarely will you hear a lawmaker use a tenant of their particular religion be used as a way to endorse or oppose a bill. Think of it this way; a bill comes before the House proposing that all businesses should close on Sunday because it says in the Ten Commandments to keep the Sabbath holy. The people of the Jewish faith have a problem. Their religion says that Saturday, not Sunday is the Sabbath. Many shoppers would have a problem with that because the only day they get off work is Sunday. The list would go on and on. Here's another example; Catholics, Lutherans and other Christian religions want Good Friday to be a National Holiday. Now here come the Jewish Americans, the Muslim Americans, The Hindu Americans, The Buddhist Americans and a host of other religous people demanding that their holidays be observed also. What is good for the goose is good for the gander, correct? I could sit here and write thousands of pages of why our founding fathers wanted to separate church and state, but the main reason, and here it is; because of the way people were persecuted in "merry old England" that caused them to emigrate to America in the first place. Our nation's founders did not want to emulate the government that they were seceding from. It makes sense too. This separation of church and state has worked well for our nation, enabling America to become a haven for people of all religions. This is one of the foremost reasons why America has become the greatest nation on the planet.