You are missing the point, It has nothing to do with "under God", it has to do with the Court misreading and misapplying the plain words of the Constitution.
The so called "wall" is meant to protect all religions from the ESTABLISHMENT of a PARTICULAR brand of religion. It was never meant to prevent the mention of a higher power. In this country we enjoy freedom OF religion. Not freedom FROM religion. Get it?
Yes, we do have freedom from religion, if we want it. If an American adult doesn't want to go to a house of worship or to tithe, no one can make him. You have the right to knock on my door and tell me about your religion and I have the right to say no thanks.
What do you really mean when you say we don't have "freedom from religion"? That every American must have a religion, but has the freedom to choose which one? I don't think so.
They are the same thing when it comes to the use of Government power and tax dollars. While you are free to practice almost any religion you choose, if tax dollars extorted from you by threat of force are used to support any religion you do not have "freedom OF religion".