If religion is fairy tale and isn't something to be even taken seriously, then...

[Angrboda]

Article 1, Section 8 of the United States Constitution grants the U.S. government the power "To coin Money, [and] regulate the Value thereof," so the value of U.S. currency is backed by the power and force of the United States government, including the world's most powerful military, and one of the world's most effective police forces.

But please, make more ludicrous arguments which do nothing but show how desperate you are for anything to justify your beliefs. Maybe if you had more faith, you wouldn't feel the need to do so.