Fr Gregory answers an email, discussing the virtue of faith as well as the dynamic between certainty and faith. It’s a good read and I absolutely love the summarizing paragraphs:

“For St Gregory Nyssa, to wrap this up, this is the source of human perfectablity.  We are in a constant state of change, and so we are forever imperfect.  This however is not due to any lack on our part but is inherent in being a creature and it our changeability that makes it possible for to grow in perfection, that is become like God Who does not change.  We can only become like the Unchanging God, that is perfect, to the degree that we are willing to change “and change frequently” in Gregory’s formulation.

“To the degree that I imagine I have intellectual certitude–that is that now I understand God or the Christian life in an exhaustive sense–to that degree I am a fool and living not by faith but something else entirely.  A life of faith requires that I am constantly changing, growing and re-evaluating myself and my life not only in the Light of the Unchanging God but also the ever changing circumstances in which I (quite literally) find myself.”