 What it simply says is Congress can't make a law establishing religion. In other words, we don't have to all be Anglican like we were under King George. But it also says the government can't get in our way of worshiping as we see fit. And as you said righteously in the declaration, it says by the creator, in the first Thanksgiving proclamation for Washington, it talks about God and the Lord and him and his and all of that over and over again.