Having "In God We Trust" on our currency (and in some US states, in our schools) is a violation of the concept of separating church and state, and should be removed.
Not much explanation needed for this one, but I will leave an article discussing the part about schools being required to display "In God we trust"
I hope parents sue, because it's 100% a violation of the separation clause. "In God we Trust" historically was not secular in any sense, it was a specific overreaction to communist atheism in the 1950s. It should have never been added to our money, it should not be the national motto as it is not at all secular and this display requirement is absurd and unnecessary.