The essential difference between orthodox Christianity and the various heretical systems is that orthodoxy is rooted in paradox. Heretics, as Irenaeus saw, reject paradox in favour of a false clarity and precision. But true faith can only grow and mature if it includes the elements of paradox and creative doubt. Hence the insistence of orthodoxy that God cannot be known by the mind, but is known in the obscurity of faith, in the way of ignorance, in the darkness. Such doubt is not the enemy of faith but an essential element within it. For faith in God does not bring the false peace of answered questions and resolved paradoxes. Rather, it can be seen as a process of 'unceasing interrogation'.
-- Kenneth Leach, "True God"