A wonderful article, The Church as Paradox, (pp.24-29) in the November 2009 issue of the Homiletic & Pastoral Review (requires subscription) reminds us of the dual nature of the Church.
“The Church is divine in it origin but remains human in its membership. For that reason it can appear as deeply flawed. According to its founder, holiness is not a prerequisite for membership; “For I have come to call not the righteous but sinners” (Matt. 9:13).
“A study of the Church under both dimensions requires looking at the Church historically and sociologically as well as theologically. Any single method would result in only a partial picture and a less than full understanding. Studying the Church on a purely theological level would result in what can be called an idealist ecclesiology, a description of what the Church should be ideally. But that bears little resemblance to the actual Church as it has been experienced in history. Reading the actual history of the Church, even when written by sympathetic authors, can be quite disturbing.
“Examples of the dark side of the Church are abundant: certain aspects of the Crusades; the Inquisition, which has remained for centuries a principal—and for many a conclusive—argument that the Catholic Church is the archenemy of human freedom; the confusion about papal succession in the fourteenth century; the corruption within the Church that contributed greatly to the Protestant Reformation; the failure of the Church to uphold consistently basic human values by becoming identified with a dominant class that was often unjust and oppressive of minorities; and most recently, clergy sexual abuse.” (pp 26-27)