St. Symeon the New Theologian ca. 949-1022
John the Theologian says, To this end was the Son of God manifested, that He might destroy the works of the devil (1 Jn. 3:8). The works of the devil are every kind of sin: envy, lying, cunning, hatred, hostility, remembrance of wrongs, slander, anger, rage, pride, vainglory, lack of mercy, covetousness, thievery, unrighteousness, evil lust, quarrelsomeness, dissatisfaction, irritability, ridicule, making oaths, forgetfulness of God, lack of human mercy, and every other evil. And so for those who are called Christians and do such works of the devil, what benefit is there from the fact that they are called Christians, when the manifestation of the Son of God has not destroyed in them these works of the devil?
If anyone will say that some of those who are like this explain the Divine Scripture, theologize, preach Orthodox dogmas — let them know that it is not in this that the work of Christ consists. John the Theologian does not say, to this end was the Son of God manifested, that certain ones should theologize and orthodoxize, (that is, pride themselves in their Orthodoxy — trans. note) but that He might destroy the works of the devil. Concerning such ones, I shall say that first one must clean the vessel of every filth and then place it in myrrh, lest the myrrh itself become defiled, and in place of fragrance there should come from it an evil smell. The Son of God, the Word, did not become man in order only that men should believe in the Holy Trinity, glorify It, and theologize about It, but in order to destroy the works of the devil. In whomever among those who have received the faith of Christ the works of the devil shall be destroyed, to him may be entrusted the mysteries of theology and Orthodox dogmas. (The First Created Man, Homily 10 Adam’s Sin and Our Salvation: 4)