When someone is beginning the spiritual life, he should not study a lot, but instead watch himself and guard his thoughts. A strong person is the one who chews well, not the one who eats a lot.
Let us go forward with the heart completely attentive and the soul fully conscious. For if attentiveness and prayer are daily joined together, they become like Elias' fire-bearing chariot, raising us to heaven. What do I mean? A spiritual heaven, with sun, moon and stars, is formed in the blessed heart of one who has reach a state of watchfulness, or who strives to attain it.
No Christian believing rightly in God should ever be off his guard. He should always be on the look-out for temptation, so that when it comes he will not be surprised or disturbed, but will gladly endure the toil and affliction it causes, and so will understand what he is saying when he chants with the prophet: 'Prove me, O Lord, and try me' (Ps. 26:2 LXX). For the prophet did not say, 'Thy correction has destroyed me,' but, 'it has upheld me to the end' (Ps. 18:35 LXX).
Unceasing prayer means to have the mind always turned to God with great love, holding alive our hope in Him, having confidence in Him whatever we are doing and whatever happens to us. That is the attitude that the Apostle had when he wrote: ‘Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or peril? Neither death nor life nor any other creature shall be able to separate us from the love of God in Christ Jesus.’ [cf. Rom. 8:35-38]
Watch constantly, learning to understand God's law, for this warms the heart with heavenly fire. Guard your lips from the idle word, or empty talk, lest the heart gets used to evil words.
And pray ye without ceasing in behalf of other men. For there is in them hope of repentance that they may attain to God. See, then, that they be instructed by your works, if in no other way. Be ye meek in response to their wrath, humble in opposition to their boasting: to their blasphemies return your prayers; in contrast to their error, be ye steadfast in the faith; and for their cruelty, manifest your gentleness. While we take care not to imitate their conduct, let us be found their brethren in all true kindness; and let us seek to be followers of the Lord (who ever more unjustly treated, more destitute, more condemned? ), that so no plant of the devil may be found in you, but ye may remainin all holiness and sobriety in Jesus Christ, both with respect to the flesh and spirit.
We must accomplish the course of our earthly pilgrimage with the greatest attention and watchfulness over ourselves, unceasingly calling upon God in prayer for help.
It is impossible for the soul to attain anything spiritual and pleasing to God, or to be free of inner sin, without guarding of the mind and purity of heart, in other words, without sobriety... If with God's help we gain something daily through our sobriety, we should take care not to enter into communication with other people without discrimination, lest we suffer loss through our converse with them and are led into temptation.
Your enemy, the evil one, the father of lies, does not slumber; and endeavors, by every means open to him, to harden your heart --- to make it false and crafty, to drive out from it faith and hope in God - together with love for Him and love and sympathy for your neighbor - and to occupy you with worldly, temporal interests. Watch yourself, watch the thoughts of your heart, and do not bind yourself in the chains of worldly desires and pleasures. Let your happiness be in the one God and the human soul.
Watchfulness cleanses the conscience and makes it lucid. Thus cleansed, it immediately shines like a light that has been uncovered, banishing such darkness. Once this darkness has been banished through constant and genuine watchfulness, the conscience then reveals things hidden from us.
The heart which is constantly guarded, and is not allowed to receive the forms, images and fantasies of the dark and evil spirits, is conditioned by nature to give birth from within itself to thoughts filled with light. For just as coal engenders a flame, or a flame lights a candle, so will God, who from our baptism dwells in our heart, kindle our mind to contemplation when He finds it free from the winds of evil and protected by the guarding of the intellect.