The quickest way to ascend to the kingdom of heaven by the short ladder of the virtues is through effacing the five passions hostile to obedience, namely, disobedience, contentiousness, self-gratification, self-justification and pernicious self-conceit. For these are the limbs and organs of the recalcitrant demon that devours those who offer false obedience and consigns them to the dragon of the abyss. Disobedience is the mouth of hell; contentiousness its tongue, whetted like a sword; self-gratification its sharp teeth; self-justification it gullet; and self-conceit, that sends one to hell, is the vent that evacuates its all-devouring belly.
If through obedience you overcome the first of these–disobedience–you cut off all the rest at a stroke, and with a single swift stride attain heaven. This is the truly ineffable and inconceivable miracle wrought by our compassionate Lord: that through a single virtue, or rather, a single commandment, we can ascend straightway to heaven, just as through a single act of disobedience we have descended and continue to descend into hell.
~St Gregory of Sinai