Fr Thomas Hopko was a bright and shining light in the Orthodox Church, particularly in America. His words and teaching were powerful as well as illumining, they were deep, and yet you could grasp his point, and most of all they were words that somehow drew you in and stoked the fires of curiosity in those who were listening. In his capable hands, what might have merely remained "mysterious" about Orthodox Christianity became the riches of the Faith that so many people are seeking (as all men and women should).
Fr Hopko wrote a four-volume set of books that are part catechesis, part theological treatise, and part introduction to the "True Faith". You can find all four volumes online, and they are freely available to read: