Before the war begins, seek out your ally; before you fall ill, seek out your physician; and before grievous things come upon you, pray, and in the time of your tribulations you will find Him, and He will listen to you.
The most important thing in any good effort and the height of all activities is to persevere in prayer, by means of which we can always acquire through supplication the other virtues from God as well.
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.
Ask the angels and the saints to intercede for you, just as you'd ask people who are alive. Stand face to face with them, in the belief that they are also standing face to face with you.
How can one avoid distractions in prayer? If one abides in the presence of God. Indeed, when in the presence of one's judge and one's master, and speaking with him, one does not let one's eyes wander elsewhere. How much more should the one who approaches the Lord never turn away the eye of his heart, but fix it on Him who searches the reins and the heart.
The one who prays ought never to halt his movement of sublime ascent toward God. For just as we should understand the ascent 'from strength to strength' as the progress in the practice of the virtues, 'from glory to glory' (2 Cor. 3:18) as the advance in the spiritual knowledge of contemplation, and the transfer from the letter of sacred writing to its spirit, so in the same way the one who is settled in the place of prayer should lift his mind from human matters and the attention of the soul to more divine realities.
When we return to prayer after a period of reading we find a rejuvenated and invigorated soul, stirred by the desire for God. The best form of prayer is one that implants the clearest idea of God in the soul and thus makes space for the presence of God within us. We become a temple of God when our continuous meditation on Him is not constantly interrupted by ordinary worries, and the spirit is not disturbed by unexpected emotions. Thus, in flight from all things, the spirit who loves God can approach God who drives out everything that leads us to evil, and holds steadfastly to everything that leads to virtue.
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.