Gregory the Theologian says:
When the most sacred body of Christ is received and eaten in a proper manner, it becomes a weapon against those who war against us, it returns to God those who had left Him, it strengthens the weak, it causes the healthy to be glad, it heals sicknesses, and it preserves health. Through it we become meek and more willing to accept correction, more longsuffering in our pains, more fervent in our love, more detailed in our knowledge, more willing to do obedience, and keener in the workings of the charismata of the Spirit. But all the opposite happens to those who do not receive Communion in a proper manner.
St. Ephraim the Syrian writes:
Brothers, let us practice stillness, fasting, prayer, and tears; gather together in the Church; work with our hands; speak about the Holy Fathers; be obedient to the truth; and listen to the divine Scriptures; so that our minds do not become barren (and sprout the thorns of evil thoughts). And let us certainly make ourselves worthy of partaking of the divine and immaculate Mysteries, so that our soul may be purified from thoughts of unbelief and impurity, and so that the Lord will dwell within us and deliver us from the evil one.
St. Theodore the Studite wondrously describes the benefit one receives from frequent Communion:
Tears and contrition have great power. But the Communion of the sanctified Gifts, above all, has especially great power and benefit, and, seeing that you are so indifferent towards it and do not frequently receive it, I am in wonder and great amazement. For I see that you only receive Communion on Sundays, but, if there is a Liturgy on any other day, you do not commune, though when I was in the monastery each one of you had permission to commune every day, if you so desired. But now the Liturgy is less frequently celebrated, and you still do not commune. I say these things to you, not because I wish for you simply to communehaphazardly, without preparation (for it is written: But let a man examine himself, and so let him eat of the Bread, and drink of the Cup. For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lords body and blood [1 Cor. 11:2829]). No, I am not saying this. God forbid! I say that we should, out of our desire for Communion, purify ourselves as much as possible and make ourselves worthy of the Gift. For the Bread which came down from heaven is participation in life: If any man eat of this bread, he shall live for ever: and the bread that I will give is My flesh, which I will give for the life of the world (Jn. 6:51). Again He says: He that eateth My flesh, and drinketh My blood, dwelleth in Me, and I in him (Jn. 6:58).
St. Anastasios of Antioch confirms this:
If we fall into some small, pardonable sins on account of our being human, either with our tongue, our ears, our eyes, and we fall as victims of deceit into vainglory, or sorrow, or anger, or some other like sin, let us condemn ourselves and confess to God. Thus let us partake of the Holy Mysteries, believing that the reception of the divine Mysteries is unto the purification of these small sins (though not the grave and evil and impure sins which we may have committed, regarding which we should seek the Mystery of Confession).
Chrysostom likewise says:
For Great Lent occurs but once a year. But we celebrate Pascha (that is, we receive Communion) three times a week or even four. Or, to say it better, as often as we like. For Pascha does not consist of fasting, but of the Offering and Sacrifice which takes place during the daily gathering. And as testimony that this is true, listen to Paul, who says: Christ our passover [pascha] is sacrificed for us (1 Cor. 5:7)
. Therefore, as often as you partake of Communion with a pure conscience, you celebrate Pascha; not when you fast, but when you partake of that Sacrifice
. The catechumen never celebrates Pascha, even though he may fast every year during Lent, because he does not commune in the Offering. So then, even the person who did not fast, if he approaches with a pure conscience, celebrates Pascha, be it today, tomorrow, or any time he partakes of Communion. For good and proper preparation for Communion is not judged by lengths of time, but by a pure conscience.