One who is firm in faith, if he will speak and contend with heretics or unbelievers, will never be disturbed, because he has within himself Jesus, the Source of peace and stillness. And such a one, after contending peacefully, can with love bring many heretics and unbelievers to the knowledge of our Savior Jesus Christ. Wherefore, O brother, since the judging of other subjects is above your measure, then keep to the royal path, I say, the faith of the 318 Holy Fathers [of the First Ecumenical Council] in which you were baptized: it includes within itself precisely everything for those who understand completely . . . . From now on do not be concerned over subjects which are not assigned to you, for the Lord has taken all cares away from you . . . . Pray for me, O brother, that it may not be said of me: Thou that teachest another, teachest thou not thyself? (Rom. 2:21).
–Answer 58 in Guidance Twoard Spiritual Life 2e, tr. by Father Seraphim Rose (St Herman of Alaska Brotherhood 2002)