Prayer demands that the mind should be pure of all thought and should admit nothing not belonging to prayer, even if it were good in itself. As if inspired by God the mind should withdraw from all things and hold its converse with Him alone.
O man, learn the humility of Christ and the Lord will give you to taste of the sweetness of prayer. And if you would pray cleanly, be humble and temperate, confess yourself thoroughly, and prayer will feel at home in you. Be obedient, submit with a good conscience to those in authority; be content with all things, and your mind will be cleansed of vain thoughts. Remember that the Lord sees you, and be fearful lest you anywise offend your brother, whom neither dispraise nor grieve, even by a look, and the Holy Spirit will love you and will Himself be your help in all things.
The head of every good striving and the pinnacle of all corrections is to persevere in prayer, by which we may ever obtain, through entreaty of God, all the other virtues as well. By prayer those who are worthy partake of the sanctity of God and spiritual activity and the union of the mind with the Lord in unutterable love. He who constantly forces himself to endure in prayer is roused by spiritual love to Divine fervor and flaming desire towards God, and he receives, according to his measure, the grace of spiritual, sanctifying perfection.
The truth and saving properties of our holy faith are clearly revealed by the fact that not a single Sacrament, not a single faithful prayer are left fruitless in us, but they bring and manifest their power from heaven upon our souls and bodies, cleansing our sins, and giving peace to our souls in accordance with the words of our Savior: 'Come unto Me, all ye that labor and are heavy laden, and I will give you rest' (Mt. 11:28); and delivering us from spiritual afflictions and bodily sicknesses! No, we never pray in vain to the Lord, or to the most holy Virgin, or to the angels and saints, but we receive all that we ask them for, and that tends to our salvation.
Fire makes iron impossible to touch, and likewise frequent prayer renders the intellect more forceful in its warfare with the enemy. That is why the demons strive with all their strength to make us slothful in attentiveness to prayer, for they know that prayer is the intellect's invincible weapon against them.
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
Now you become angry and fainthearted and grieved, thinking that the heavenly Father is slow in answering. But I tell you that this will also happen as you desire—it will definitely happen—but first it takes prayer with all your soul, and then you must wait. And when you have forgotten your request and have ceased asking for it, it will come to you as a reward for your patience and endurance. When you reach the verge of despair while praying and seeking, then the fulfillment of your request is near. Christ wants to heal some hidden passion within you, and this is why He delays in granting your request. If you obtain it sooner, when you demand it, your passion remains uncured within you. If you wait, you obtain your request and the cure of the passion. And then you rejoice exceedingly and give warm thanks to God Who arranges all things in wisdom and does everything for our benefit.
Unless humility and love, simplicity and goodness regulate our prayer, this prayer - or, rather, this pretence of prayer - cannot profit us at all. And this applies not only to prayer, but to every labor and hardship undertaken for the sake of virtue.