So far, dear reader, I have spoken to you of the four weapons required to overcome the enemies in unseen warfare, namely non-reliance on oneself, an unshakeable hope in God, resisting and struggling with sin, and prayer. Now I want to indicate to you another powerful weapon in this warfare, namely, the most holy sacrament of the Eucharist. This sacrament is the highest among sacraments, and is the most powerful and effective of all spiritual weapons. The four weapons of which we have spoken receive their power from the forces and gifts of grace, obtained for us by the blood of Christ. But this sacrament is Christ’s blood itself, and His flesh itself, in which Christ is Himself present as God. When we use those four weapons, we fight the enemy with the power of Christ; in the latter case our Lord Christ Himself strikes down our enemies through us, or in company with us. For he who eats Christ’s flesh and drinks His blood abides with Christ, and He in him, as He said: ‘He that eateth my flesh, and drinketh my blood, dwelleth in me, and I in him’ (John vi. 56). Therefore, when we overcome the enemies, it is the blood of Christ which overcomes, as it is written in Revelation: ‘and they overcame him’ (the slanderous devil) ‘by the blood of the Lamb’ (Rev. xii. 11).

This most holy sacrament, this all-conquering weapon, or rather Christ present in this sacrament, can be actively received in a twofold manner: first, sacramentally, in the sacrament of Christ’s flesh and blood, with the necessary preparation, that is, contrition, confession, purification by penance and the required fast; secondly – inwardly and spiritually in mind and heart. The first may take place as often as outer circumstances, inner state and the discretion of one’s spiritual Father allow; the second can take place every moment; so you may always have this all-powerful weapon in your hand and constantly wield it against your enemies. So harken to this and partake of the Holy Mysteries of Christ as often as possible, so long as you have the permission of your spiritual Father. But strive to partake of Christ our Lord inwardly and spiritually without ceasing.

Source: Unseen Warfare as edited by Nicodemus of the Holy Mountain and revised by Theophan the Recluse, St. Vladimir’s Seminary Press.