The answer regarding whether the US was founded upon Christianity is I believe more complex than the OP has stated. Were many of the original settlers Christians? Yes. Was American culture strongly influenced by Christianity? Yes. Was the original intent of the Constitution to establish Christianity in America? No.
I think the founders did have Judeo-Christian principles in mind when writing the Constitution. Historical writing shows the faith and belief of many of the founders and that they were very much influenced by their Christian beliefs. I also think that many of the quotes found which seem to be a slam against Christianity are really an outward showing of distaste for the organized Christian religions of the time and the hypocrisy of not following Christian teachings.
In other words, many of those who professed to be Christian did not actually strive to follow Christian teachings. I view some of our founders as wanting to change this and for people to return to actually following Christian teachings. Yes, there were deists among the founders, however, I think the lack of Christians striving to follow Christian teachings may have precipitated some to be disenfranchised with organized religion and "created" these deists.
Regardless, it is clear to me that our country would be much different without the influence of Christianity through the countrys individual Christians. There are too many who try to diminish the positive effect Christianity has had on America, including the framing of the Constitution. In the end, each country is built by the individuals that occupy it and the majority of the founding Americans were Christian. To try and say this did not have an effect on the establishment of America and on writing the Constitution would be incorrect.
Well, you makd some valid points such as Christianity has had a great positive influence over all of America. No one is doubting that. Christianity is not the question.
The US Constitution is the law that the founders BASED THIS COUNTRY ON.
The Constituion, specifically the seperation of powers, was adopted from the Greek Constitution.
The Greeks at that time were not Christian.
The problem that I see here is a complete failure of the religous right TO ADMIT that it is the US Constitution THAT THIS COUNTRY IS FOUNDED ON.
Never was religion. Hint: Christianity is a religion.
We are a nation of LAWS, not men and their Gods and religion.
Now admit it and get over it. You will feel better.
The United States of America was founded on LAWS.