It is as necessary for a man to say the Jesus Prayer as it is for a ship in danger to send out steadily the S.O.S. signal: Lord Jesus Christ have mercy on me.
Not only we are in this assembly (in the Church), but also the prophets and the apostles and all the saints; and what is most important of all - among us is Jesus Christ Himself, the Master of everything.
What does it mean to be as wise as a serpent? When a serpent is attacked, it is willing to have much of its body severed, as long as it saves the head. So to be wise as a serpent means to be willing to lose everything - your wealth, your reputation, your friends - as long as you save your faith. Your faith is your head, by which you learn all truth; and by that truth your soul is set free. We should, however, recognize that the wisdom of the serpent is not enough; we must be honest and innocent as doves. Indeed it is the combination of wisdom and innocence that creates virtue. The person who is wise as a serpent can sustain the most terrible attacks and still continue to flourish as a disciple of Christ. The person who is innocent refuses to retaliate against those who make the attacks. To be as innocent as a dove means never to take revenge on those who wrong you or undermine you. Unless wisdom is tempered by innocence, one attack provokes another, and conflict continues without end. Unless innocence is tempered by wisdom, a person is so vulnerable that he will not even survive a single attack. Rest assured that no one can ever take away your faith; your wisdom guards against that. But be careful never to bear a grudge against anyone who does you wrong.
What does spoil repentance is being again entangled in the same evils. 'For there is one' we read, 'who builds, and one who pulls down, what have they gained more than toil? He who is dipped in water because of contact with a dead body, and then touches it again, what has he gained by his washing?' Even so if a man fasts because of his sins, and goes his way again, and does the same things, who will hear his prayer? And again we read 'if a man goes back from righteousness to sin the Lord will prepare him for the sword,' and, 'as a dog when he has returned to his vomit, and become odious, so is a fool who by his wickedness has returned to his sin.'
We cannot be saved by seeking just our own individual salvation; we need to look first to the good of others. In warfare, the soldier who takes to flight to save his own skin brings disaster on himself as well as on the others, whereas the good soldier who takes up arms on behalf of his comrades saves his own life along with theirs.
Why then is this day called Theophany? Because Christ made Himself known to all -- not then when He was born -- but then when He was baptised. Until this time He was not known to the people. And that the people did not know Him, Who He was...
For nothing can so make a man an imitator of Christ as caring for his neighbors. Indeed, even though you fast, or sleep on hard ground, or even suffer unto death, but should take no thought for your neighbor, you have done nothing great; despite what you have done, you will still stand far from this model of a perfect Christian.
Remember that a good action is always either preceded or followed by temptations. God permits this so that the virtue, exercised in that particular action, may be confirmed, consolidated, steeled.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Behold, this is the true and the Christian humility. In this you will be able to achieve victory over every vice, by attributing to God rather than to yourself the fact that you have won.
Brethren, let us also occupy yourselves with noetic prayer… and seeking God’s mercy, cry out with a humble heart from morning till night and if possible all night long, saying constantly: 'Lord Jesus Christ, Son of God, have mercy on us.'
One time St. Nicodemos, on a feast day, was walking toward the Great Lavra (on Mt Athos). On his way he came across a kellion where he spent the night. At midnight he saw an elder and his accompanying monks entering the church. He secretly went in also, and there he saw the elder and his subordinate monks uttering the Jesus Prayer ('Lord Jesus Christ, Son of God, have mercy on me'), sometimes in a kneeling position, sometimes standing up. And at the time of the Holy Communion, he saw all their faces shining only a little less dimly than the sun.