According to the description, the audience was the "Evangelical Orthodox" group that was eventually received into the Antiochian Church. Some of them were eventually ordained, Fr Peter Gilquist, of note. So it was not a clergy retreat. That group began with Campus Crusade for Christ but started going deep on history, the Fathers, liturgics, etc. until they became Orthodox.
"We do not believe in magic. We do not believe in mechanics. We believe in grace." Such an important point when trying to understand our life in Christ in and through the Holy Mysteries.