"Ideology" does not mean political theory or principle, even though many journalists and some professors commonly employ the term in that sense. Ideology really means political fanaticism--and, more precisely, the belief that this world of ours may be converted into the Terrestrial Paradise through the operation of positive law and positive planning. The ideologue--Communist or Nazi or of whatever affiliation --maintains that human nature and society may be perfected by mundane, secular means, though these means ordinarily involve violent social revolution. The ideologue immanentizes religious symbols and inverts religious doctrines.
What religion promises to the believer in a realm beyond time and space, ideology promises to everyone--in society. Salvation becomes collective and political.--Russell Kirk