If the saints, who had attained passionlessless, had to be vigilant over themselves so as not to fall from their state of grace - then all the more is daily attentiveness and concern over our eternal salvation necessary for us sinners. The fact that we are still alive means that the Lord patiently endures our sins and awaits our amendment, and if someone lawfully labors for his salvation, the Lord takes him at a time when he becomes worthy of God’s mercy.
The first duty of a Christian, of a disciple and follower of Jesus Christ, is to deny oneself. To deny oneself means to give up one's bad habits, to root out of the heart all that ties us to the world; not to cherish bad desires and thoughts; to quench and suppress bad thoughts; to avoid occasions of sin; not to do or desire anything from self-love but to do everything out of love for God. To deny oneself means, according to the Apostle Paul, to be dead to sin and the world, but alive to God.
Often when someone throws a rock at a dog, rather than rushing at the person who threw the stone, the dog will run and bite the stone. We do the same thing. The tempter uses someone else to tempt us, either in word or deed, and, rather than deal with the tempter who threw the stone, we bite the rock, our fellow man that the hater of the good used against us.
He who chooses maltreatment and dishonor for the sake of truth is walking on the apostolic path; he has taken up the cross and is bound in chains (cf. Mt 16:24). But when he tries to concentrate his attention on the heart without accepting these two, his intellect wanders from the path and he falls into the temptations and snares of the devil.
One of the Fathers said: just as it is impossible for a man to see his face in troubled water, so too the soul, unless it be cleansed of alien thoughts, cannot pray to God in contemplation.
The Martyrs won Paradise through their blood; the Ascetics, through their ascetic life. Now you, my brethren, who have children, how will you win Paradise? By means of hospitality, by giving to your brothers who are poor, blind, or lame.
I must tell you that annoying incidents are unavoidable in this life. Those who are experienced in the spiritual life say that such incidents can even bring profit to the soul. Through annoying incidents we come to recognize that we are impatient - and if we are impatient, that means we are proud. And this awareness should dispose us to self-reproach and repentance, and to asking mercy from the Lord in prayer. But without annoying incidents a man is inclined to conceit.
In words of boastfulness and self-justification there always lie concealed contrariness and pride, from which God turns away. After sinning one ought immediately to 'flee.' But, you will say, where? To the calm haven of heartfelt repentance. Every night before you go to sleep, tell God, the Knower of Hearts, all the sins you have committed in deed, word, and thought, and believe that God receives your heartfelt repentance. At the same time try to render your heart contrite by the memory of sudden death.
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.
Love giving hospitality, my child, for it opens the gates of Paradise. In this you also offer hospitality to angels. 'Entertain strangers so that you won't be a stranger to God.'