Nikiphoros the Monk: On Watchfulness and the Guarding of the Heart
If you ardently long to attain the wondrous divine illumination of our Savior Jesus Christ; to experience in your heart the supracelestial fire and to be consciously reconciled with God; to dispossess yourself of worldly things in order to find and possess the treasure hidden in the field of your heart (cf Matt. 13:44); to enkindle here and now your soul's flame and to renounce all that is only here and now; and spiritually to know and experience the kingdom of heaven within you (cf. Luke 17:21): then I will impart to you the science of eternal or heavenly life or, rather, a method that will lead you, if you apply it, painlessly and without toil to the harbor of dispassion, without the danger of being deceived or terrified by the demons. Terror of this kind we experience only when through disobedience we estrange ourselves from the life I am about to describe. This was the fate of Adam when he violated God's commandments: associating with the serpent and trusting him, he was sated by him with the fruits of deceit (cf. Gen. 3:1-6), and thus wretchedly plunged himself and all those who came after him into the pit of death, darkness and corruption.
You should, then, return; or - to put it more truly - let us return, brethren, to ourselves, rejecting once and for all with disgust the serpent's counsel and our deflection to what is base. For we cannot be reconciled with God and assimilated to Him unless we first return or, rather, enter into ourselves, in so far as this lies within our power. For the miracle consists in tearing ourselves away from the distraction and vain concerns of the world and in this way relentlessly seizing hold of the kingdom of heaven within us.
That is why the monastic life has been called the art of arts and the science of sciences. For this holy discipline does not procure us what is corruptible, so that we divert our intellect from higher to lower things and completely stifle it. On the contrary it offers us strange, indescribable blessings, that 'the eye has not seen, and the ear has not heard, and man's heart has not grasped' (1 Cor. 2:9). Henceforward 'we wrestle not against flesh and blood but against principalities, against powers, against the rulers of the darkness of this world' (Eph. 6:12). If, then, this present age is one of darkness, let us flee from it. Let us flee from it in our thoughts so that we may have nothing in common with the enemy of God. For if you choose to be a friend of this present age you are an enemy of God (cf. Jas. 4:4). And who can help an enemy of God?
Let us therefore imitate our fathers and like them let us seek the treasure within our hearts. And when we have found it let us hold fast to it with all our might, both cultivating and guarding it (cf. Gen. 2:15); for this is what we were commanded to do from the beginning. And if another Nikodimos should appear and begin to argue, saying, 'How can anyone enter into his own heart and work or dwell in it?' - as the original Nikodimos, doubting the Savior, said, 'How can someone who is old enter the second time into his mother's womb and be born?' (John 3:4) - let him in his turn hear the words, 'The Spirit blows where He wants to' (John 3:8). If we are full of disbelief and doubt about the practice of the ascetic life, how shall we enjoy the fruits of contemplation? For it is practice that initiates us into contemplation.
Doubters of this kind cannot be convinced without written evidence. Hence for the benefit of many I will include in this discourse passages from the lives of the saints and from their writings: reading them should dispel all doubt. I will begin at the beginning with St Antony the Great, and then continue with his successors, selecting and setting forth their words and actions as best I can, so as to confirm what I have been saying.