Just as breathing is necessary for life, and just as food is necessary for the sustenance of the body, so is frequent Communion necessary for the life of the soul and for the sustenance of its substance, or rather it is incomparably more necessary.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
God, the Word, made man for the salvation of our race, aware of the exceeding frailty and misery of our nature, hath not even here suffered our sickness to be without remedy. But like a skillful doctor, he hath mixed for our unsteady and sin loving heart the potion of repentance, prescribing this for the remission of sins. For after we have received the knowledge of the truth, and have been sanctified by water and the Spirit, and cleansed without effort from all sin and all defilement, if we should happen to fall into any transgression, there is, it is true, no second regeneration made within us by the Spirit through baptism in the water of the font, and wholly recreating us (that gift is given once for all); but, by means of painful repentance, hot tears, toils and sweats, there is a purifying and pardoning of our offences through the tender mercy of our God. For the fount of tears is also called baptism, according to the grace of the Master.
Take care never to receive Communion while you have anything against anyone, even if this is only a hostile thought. Not until you have brought about reconciliation through repentance should you communicate, [receive the Mysteries]. But you will learn this, too, through prayer.
Receive me today, O Son of God, as a partaker of Thy mystical Supper; for I shall not speak of Thy mystery to Thine enemies, neither give Thee a kiss as did Judas. But like a thief, I shall confess Thee. Remember me, O Lord, when Thou comest into Thy kingdom.
If Christ is in you through the frequent communion of the Holy Sacrament, then be yourself wholly like unto Christ: meek, humble, long-suffering, full of love, without attachment to earthly things, meditating upon heavenly ones, obedient, reasonable. Have His spirit unfailingly within you.
The Holy Eucharist is the first, most important, and greatest miracle of Christ. All the other Gospel miracles are secondary. How could we not call the greatest miracle the fact that simple bread and wine were once transformed by the Lord into His very Body and His very Blood, and then have continued to be transformed for nearly two thousand years by the prayers of priests, who are but simple human beings? And what is more, this mystery has continued to effect a miraculous change in those people who communicate of the Divine Mysteries with faith and humility.
When you shed floods of tears during prayer, do not exalt yourself for this, as though you were above many others. It is that your prayer has received help from above, so that, having zealously confessed your sins, you may incline the almighty to mercy by your tears.
Many times, weeping conquers God, if one can say that; and He is truly overcome. For gladly is the Merciful One constrained by tears -- But tears of the spirit And not those caused by afflictions of the body. Indeed, we weep for the dead, and we cry out over blows, For the flesh is clay and is subject to never-ending flow of tears. Let us, then, lament from our hearts In the way in which the Ninevites in their contrition opened Heaven And were heeded by the Savior. Indeed, He received their repentance.
In the beginning there are a great many battles and a good deal of suffering for those who are advancing towards God and afterwards, ineffable joy. It is like those who wish to light a fire; at first they are choked by the smoke and cry, and by this means obtain what they seek -- as it is said, 'Our God is a consuming fire' -- so we also must kindle the divine fire in ourselves through tears and hard work.
Thus should we weep for the forgiveness of our sins. The words of the bearer of the purple should convince us of this: 'Going they went and wept, casting their seed; but coming they shall come with joyfulness, carrying their sheaves (Ps. 125:6);' as well as the words of St. Isaac the Syrian: 'Moisten your cheeks with the tears of your eyes, that the Holy Spirit may abide in you, and cleanse the filth of your malice. Move your lord with your tears, that He may help you' (homily 68).