God has required only one thing from you, that every time you are disturbed by something, you should immediately restore peace in yourself, and thus should remain undisturbed in all your actions and occupations. You must know that this requires patience; for just as a city is not built in a day, you cannot expect to gain inner peace in a day. For gaining inner peace means building a house for the God of peace and a tabernacle for the Almighty, and in this way becoming a temple of God. You must also know that it is God Himself Who builds this house in you, and without Him all your labor will be in vain, as it is written: ‘Except the Lord build the house, they labor in vain that build it’ (Ps. 126:1).
Lorenzo Scupoli, ‘Spiritual Combat’ and ‘Path to Paradise,’ revised as ‘Unseen Warfare’ by Nicodemos of the Holy Mountain and Theophan the Recluse (eds)