Most definitely not.  Our government was founded on sound Christian principles.  America believes strongly that anyone can come here and practice any religion freely without government involvement.  Recently though, this has been true for every religion except Christianity.  There is nothing wrong with having the ten commandments posted outside of government buildings and such, especially since most of us do believe that there is one God, and the ten commandments are a great moral compass (thy shalt not kill is an excellent commandment, don't you think?).