“The grace of the Holy Spirit acting externally was also reflected in all the Old Testament prophets and Saints of Israel. The Hebrews afterwards established special prophetic schools where the sons of the prophets were taught to discern the signs of the manifestation of God or of Angels, and to distinguish the operations of the Holy Spirit from the ordinary natural phenomena of our graceless earthly life.”
(St. Seraphim of Sarov, ‘Conversations’)