Theodicy, in its classical form, requires the adherent of a theistic faith to reconcile the existence of an omnipotent, omniscient and morally perfect God with the existence of evil. The so-called problem of evil has a venerable ancestry, extending beyond the Christian era, and was apparently first formulated by Epicurus (341-270 BC) in the form of a dilemma which perhaps receives its most succinct formulation in the words of David Hume:

A long strand in the history of theology, stemming from St Augustine via St Thomas Aquinas and the Reformers to Schleiermacher and modern times, has addressed itself to the task of reconciling God's omnipotence, omniscience and benevolence with the existence of evil. And yet, despite the efforts of these and other theologians, the thought persists in many quarters that theodicy is perhaps one of the least satisfactory areas of the theological enterprise. Confronted with the seemingly innumerable ‘solutions’ to the problem of evil that have been advanced over the centuries, one cannot help thinking that Kant's complaint about metaphysics is probably just as applicable to theodicy: