St. Basil of Caesarea, also called Saint Basil the Great (330 – January 379), was a bishop of Caesarea Mazaca in Cappadocia (modern-day Turkey). He was an influential theologian who supported the Nicene Creed and opposed the heresies of the early Christian church. Together with Pachomius, he is remembered as a father of communal (coenobitic) monasticism in Eastern Christianity. Basil, together with his brother Gregory of Nyssa and his friend Gregory of Nazianzus, are collectively referred to as the Cappadocian Fathers.
“Just as when a sunbeam falls on bright and transparent bodies, they themselves become brilliant too, and shed forth a fresh brightness from themselves, so souls wherein the Spirit dwells, illuminated by the Spirit, themselves become spiritual, and send forth their grace to others. Hence comes foreknowledge of the future, understanding of mysteries, apprehension of what is hidden, distribution of good gifts, the heavenly citizenship, a place in the chorus of angels, joy without end, abiding in God, the being made like to God, and, highest of all, the being made God. Such, then, to instance a few out of many, are the conceptions concerning the Holy Spirit, which we have been taught to hold concerning His greatness, His dignity, and His operations, by the oracles of the Spirit themselves.”
~ from: On the Holy Spirit (De Spiritu Sancto), Chap. 9