1. Those who believe it to be a virtue that they are exceedingly sad after committing sin do not understand that they do so out of pride and selfishness and are therefore guilty.
2. Keep in mind that the only winner of this invisible battle is the one who does not stop fighting and trusting God, whose help never fails those who fight in his regiments, even though sometimes He lets them suffer injuries.
3. Forgiving our enemies and doing them good is true magnanimity – one of the greatest attributes of divinity.
4. Know that if you are quick to judge and despise others, God will punish you by letting you fall into the same sin for which you judge others.
5. Remind yourself every day that “now” is in our hands, and “tomorrow” is in the hands of God, and that He who has given you the morning has not bound Himself by the promise that He will give you the evening.
6. Be zealous if you wish to prove how steadfast your hope of salvation is before God.
7. When you have a good thought in your mind, turn to God and, knowing that it was sent by Him, thank Him.
8. When you see a church, you should remember among other salvific thoughts that your soul is also the temple of God, as it is written: ye are the temple of the living God (2 Corinthians 6:16), and that is why you have to keep it pure and chaste.
9. Good feelings are silent.
10. Do not allow your heart to be overwhelmed and disturbed by sorrow, but keep it out of your heart, and soften it and tame it so that it may not interfere with your judgment and your capacity to act.
11. Never postpone your inner cleansing for a moment as soon as you notice anything wrong with yourself.
12. Prayer is a means of attracting and accepting all kinds of favors that are poured out so abundantly on us from the inexhaustible source of God’s infinite love and goodness.
13. A prayer that comes out of our hearts is like an arrow of lightning, which immediately passes through heaven and appears before the throne of the all-merciful God.
14. One cannot succeed in prayer without success in Christian life as a whole.
15. Actions come from within. If your actions are evil, it means that your inner self is not in good order.
Source: Invisible Warfare, by Elder Nicodemus the Hagiorite, of blessed memory. Fourth edition, published by the Russian St. Panteleimon Monastery on Mt. Athos. Moscow, 1904.