You write that after Communion you felt well. Glory be to God, Who comforts our unworthiness. And as regards the fact that this soon passed, here also is seen His fatherly providence for us. For continual consolation enfeebles the soul and makes it slothful, or leads to even greater harm. That is why the Lord takes it away quickly and again makes us feel our weakness, our helplessness, and our sinfulness. We must humble ourselves more, reproach ourselves, offer repentance for our sins, and not desire consolations, but patiently endure what God allows. Dryness and cooling of fervor are also permitted on account of vainglory.
Pray simply. Do not expect to find in your heart any remarkable gift of prayer. Consider yourself unworthy of it. Then you will find peace. Use the empty cold dryness of your prayer as food for your humility. Repeat constantly: I am not worthy; Lord, I am not worthy! But say it calmly; without agitation.
Fasting is an exceptional virtue; it represses bodily impulses and gives strength to the soul to fight against the poisoning of the heart through the senses, and provides it with a remedy against any past poisoning. Fasting causes the mind to be cleansed constantly. It withers up every evil thought and brings healthy, godly thoughts -- -holy thoughts that enlighten the mind and kindle it with more zeal and spiritual fervor.
If you are praised, be silent. If you are scolded, be silent. If you incur losses, be silent. If you receive profit, be silent. If you are satiated, be silent. If you are hungry, also be silent. And do not be afraid that there will be no fruit when all dies down; there will be! Not everything will die down. Energy will appear; and what energy!
Do not think that even here any one of us constantly enjoys consolation. No: here, as everywhere, flesh and mind are at war; here as everywhere, there is falling into pride and purification through humbling: here, as everywhere, we long for consolations but must learn to carry a weighty cross. This cross tests our love. Can we, do we love God even under the weight of the most bitter adversities?
You describe how bitterly you regret the inefficacy of your prayers. Beware: to wish for consolation or revelation in prayer is a sure sign of pride. Pray humbly, in perfect simplicity, seeking salvation only through forgiveness, & having faith that God will extend to you His mercy - as He did to the publican.
Most people desire and seek after prosperity in this life, and they strive to avoid sorrows. While that seems very good and pleasant, constant prosperity and good fortune do a person harm. He falls into a variety of passions and sins, and angers the Lord, while those who live a life of sorrow come closer to the Lord and more readily attain unto salvation, for the Lord called the life of happiness the broad path. The wide gates and the broad way lead to destruction, and many there be who take that way (Matthew 7:13). It is the narrow way and the strait gate which lead to life eternal, and few there be who find it (Matthew 7:14). Thus, according to His love for us, seeing the possible benefit [of sorrows] to those who are worthy, the Lord moves many off the broad road and puts them on the narrow, sorrowful path, so that in [their] patient endurance of sickness and sorrow, He might effect their salvation and grant them life eternal.
Praise God continually with spiritual hymns and always remain in meditation and in this way you will be able to bear the burden of the temptations that come upon you. A traveler who is carrying a heavy load pauses from time to time and draws in deep breaths; it makes the journey easier and the burden lighter.
Confess your sins not to the priest, but to the Lord Himself, only without hiding anything, from your whole heart. The priest is the mediator between you and God, and so the benefit of Confession depends on your open-heartedness.
My children, avoid criticism -- a very great sin. God is grieved whenever we criticize and loathe people. Let us concern ourselves only with our own faults -- for these let us feel pain; let us criticize ourselves and then we will find mercy and grace from God.
Therefore silence, prayer, obedience; when you practice these virtues with the help of God, then you will know the light of Christ is within your soul.