Discussion of theology is not for everyone, I tell you, not for everyone-it is no such inexpensive or effortless pursuit. Nor, I would add, is it for every occasion, or every audience; neither are all its aspects open to inquiry. It must be reserved for certain occasions, for certain audiences, and certain limits must be observed. It is not for all people, but only for those who have been tested and have found a sound footing in study, and, more importantly, have undergone, or at the very least are undergoing purification of body and soul. For one who is not pure to lay hold of pure things is dangerous, just as it is for weak eyes to look at the sun's brightness. What is the right time? Whenever we are free from the mire and noise without, and our commanding faculty is not confused by illusory, wandering images, leading us, as it were, to mix fine script with ugly scrawling, or sweet-smelling scent with slime. We need actually "to be still" in order to know God, and when we receive the opportunity, "to judge uprightly" in theology. Who should listen to discussions of theology? Those for whom it is a serious undertaking, not just another subject like any other for entertaining small-talk, after the races, the theater, songs, food, and sex: for there are people who count chatter on theology and clever deployment of arguments as one of their amusements. What aspects of theology should be investigated, and to what limit? Only aspects within our grasp, and only to the limit of the experience and capacity of our audience. Just as excess of sound or food injures the hearing or general health, or, if you prefer, as loads that are too heavy injure those who carry them, or as excessive rain harms the soil, we too must guard against the danger that the toughness, so to speak, of our discourses may so oppress and overtax our hearers as actually to impair the powers they had before.
Gregory of Nazianzus, On God and Christ, The Five Theological Orations and Two Letters to Cledonius: St. Gregory of Nazianzus
theology