Put aside bodily considerations when you stand in prayer, lest the bite of a flea, a gnat or a fly deprive you of the greatest gain afforded by prayer.
The soul of all practices in the Lord is vigilance. Without vigilance, all these practices are fruitless. He who is desirous of saving himself must so establish himself that he might remain continuously vigilant toward himself, not only in solitude, but also under conditions of distraction, into which he is sometimes unwillingly drawn by circumstances.
One should nourish the soul with the word of God: for the word of God, as St. Gregory the Theologian says, is angelic bread, by which are nourished souls who hunger for God. Most of all, one should occupy oneself with reading the New Testament and the Psalter, which one should do standing up. From this there occurs an enlightenment in the mind, which is in the mind, which is changed by a Divine change.
The Holy Fathers teach us how to become familiar with the Gospel, how to read it and how to understand it, what helps and what opposes its understanding. Therefore, at first you must devote more time to reading the Holy Fathers...
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.
Apostolic teaching, Beloved, exhorts us that we put off the old man with his deeds (Eph. iv. 22; Col. iii. 9), and renew ourselves from day to day by a holy manner of life. For if we are the temple of God, and if the Holy Spirit is a Dweller in our souls, as the Apostle says: You are the temple of the living God (II Cor. vi. 16); we must then strive with all vigilance that the dwelling of our heart be not unworthy of so great a Guest.
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).
What is the source from which man's will can draw suitable principles of guidance? For a non-believer, an answer to this is extremely difficult and essentially impossible. Are they to be drawn from science? In the first place, science is interested primarily in questions of knowledge and not morals, and secondly, it does not contain anything solid and constant in principles because it is constantly changing. From philosophy? Philosophy teaches about the relativity of its truths and does not claim their unconditional authority. From practical life? Even less. This life itself is in need of positive principles which can remove from it unruly and unprincipled conditions. But while the answer to the present question is so difficult for non-believers, for a believing Christian the answer is simple and clear. The source of good principles is God's will, and this is revealed to us in the Savior's teaching, in His Holy Gospel. It alone has an unconditional, steadfast authority in this regard; and it alone teaches us self-sacrifice and Christian freedom, Christian equality and brotherhood (a concept stolen by those outside the Faith). The Lord Himself said of true Christians, 'Not everyone who says to Me, Lord, Lord, will enter the kingdom of heaven, but he who does the will of My Father' (Matt. 7:21).
The more one reads and studies the Bible, the more he finds reasons to study it as often and as frequently as he can. According to St. John Chrysostom, it is like an aromatic root, which produces more and more aroma the more it is rubbed.
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.