ARTICLE 11. As the government of the United States of America is not in any sense founded on the Christian Religion,-as it has in itself no character of enmity against the laws, religion or tranquility of Musselmen,-and as the said States never have entered into any war or act of hostility against any Mehomitan nation, it is declared by the parties that no pretext arising from religious opinions shall ever produce an interruption of the harmony existing between the two countries.The United States has always been a secular nation. A look at the religious wars in European history give ample explanation why.
I'll repeat - one of the two Founding documents that matter specifically names the Creator as the giver of our Natural Rights, and all that flows from that gift.
Speculate about secularity all you want. The Creator stuff is right there in the Declaration.
No, no, no. All the Barbary Treaty is saying is that the U.S. will continue to trade and do business with these nations despite their following of and adherence to an errant sect. That doesn't prove secularism. If you read St. Augustine or St. Thomas Acquinas, they address the need for Christians to act pragmatically in the world where not only God but also the devil entwines itself regularly and prominently in human affairs. The point being, according to these theologians, that God expects us to have sufficient knowledge and spirituality to know the damned difference and to act--in events where it is necessary for us to do so--appropriately. That is the problem with atheism. It doesn't know the difference between good and evil. It treats God and Devil the same way.