The First Amendment to the Constitution protects freedom of religious expression in the public space. Having a religious phrase on the dollar bill is not contradictory. As for the American flag, it is a sacred symbol that arouses a severely regulated cult.
In God we trust (54)
This motto has only been printed since 1955 on U.S. dollars. The previous motto was”E pluribus unum” (“Of many, let us make one”). It was replaced during the Cold War, when religious America opposed Soviet atheism. It was also the result of an offensive by business circles and the religious right led by Billy Graham against the ideological effects of a very active social policy of American governments.
Religious Freedom (55)
The First Amendment to the U.S. Constitution, adopted in 1791, prohibits the Congress from enacting laws that prevent the exercise of religion. In the secular United States, the public sphere allows religious expression, unlike other secular countries that want to limit the expression of faith to the private sphere. In America, believers of all religions do not hesitate to speak publicly about their beliefs. Atheism is comparatively more frowned upon. As every dollar bill has it: “In God we trust”.
Manuscript version of the First Amendment to the American Constitution,
1789, The U.S. National Archives, facsimile.
The flag of the United States is the object of religious attention in the USA. Its use is strictly regulated. The 13 red and white lines on its side represent the founding states of the Union while the 50 stars in the upper left corner symbolize the current states of the country. It must be hoisted on public monuments 16 times a year. There is an oath of allegiance to the flag which emphasizes that it designates a united nation under the authority of God.