Should we declare the us a christian nation for national secy purposes?

without fail all the nations that are muslim harbor terrorists and all countries that dont have religion welcome in terrorists and illegals with open arms, just look at sweden and spain for example. if we declare the us to be a christian nation then people wont want to mess with us and terrorists will keep away. it doesnt violate the constitution b/c the establishment claus just applies to govt .. why are libs against this idea.?