What is Iago’s Credo in Verdi’s Otello about?

In Giuseppe Verdi’s opera Otello, Iago’s "Credo" (found in Act II) serves as a chilling exposition of his malicious philosophy. When left alone, Iago sings "Credo in un Dio crudel" ("I believe in a cruel God"), which acts as a blasphemous perversion of the creed traditionally used in the Roman Catholic mass.1

Through this aria, Iago reveals his nihilistic and malevolent worldview, asserting that humanity is the product of a cruel deity and that life is defined by suffering and nothingness. This moment underscores his role as the opera's primary antagonist, highlighting his commitment to destruction and his lack of moral conscience as he orchestrates the downfall of Otello.1