Lyric discussion by bsheitman 

Cover art for Selling Advertising lyrics by David Bazan

David Bazan explains in an interview the "Are you a Christian..." lyrics refer to not pigeonholing people based off of surface level assumptions. For example, one could assume that "Schreiber" is a Jewish last name so would he then make a bunch of stereotypical assumptions and write reviews about Ryan Schreiber's Jewishness?

here's the link I got that from: http://www.staythirstymedia.com/0307m/html/0307davidbazan.html