These virtues were indicated by the Holy Apostle Paul in his letter to the Corinthian Christians: “Now these three (virtues) remain: faith, hope, love” (1 Cor. 13:13).
What our faith should consist of, or in other words, what an Orthodox should believe in, is briefly outlined in the Creed, compiled by the holy fathers and teachers of the Church at two ecumenical councils - Nicaea (325) and Constantinople (381).