For 10 points, identify this former Church office, commonly used to refer to someone taking a position solely for the sake of argument.
Lawrence Justinian was canonized for his services in this role. Before becoming Pope Benedict XIV, Prospero Lamertini held this position for twenty years. Urban VIII caused this role to be extended and entrenched, and while  the first mention of the duties of this office is recorded under the reign of Leo X, this office was established formally by Sixtus V. This office was formally abolished by John Paul II in 1963. Formally called Promotor Fidei, the holder of this position was responsible for giving natural explanations for the miraculous acts performed by a candidate for beatification and canonization. For 10 points, identify this former Church office, commonly used to refer to someone taking a position solely for the sake of argument.
Lawrence Justinian was canonized for his services in this role.
{Devil's Advocate} [or {Advocatus Diaboli;} accept {Promoter of the Faith} or {Promotor Fidei} before it is read]