Yeah, the In God We Trust thing wasn't added until the Civil War.
So this
Because those "archaic" ideologies are the principles the country was founded on and the go-to values for how it should be run?
seems like a bit of a misconception at least with respect to the motto on currency. It doesn't have anything to do with our country's founding, and it didn't even make it to paper currency until 1957!
I'm not particularly anti-Christian, but I do stand with the Founding Fathers' belief in a secular government. To quote Madison in the Treaty of Tripoli,
As the Government of the United States of America is not in any sense founded on the Christian religion...
Washington, Franklin, Jefferson and Paine seemed to share similar sentiments.
Then on the other hand we've got Patrick Henry, who seems to be of mixed opinion on it. We've got:
It cannot be emphasized too strongly or too often that this great nation was founded not by religionists but by Christians, not on religion but on the Gospel of Jesus Christ. We shall not fight alone. God presides over the destinies of nations." - Patrick Henry