We must vigilantly guard our heart from unfitting thoughts and impressions, according to the word of the writer of Proverbs: ‘Keep thine heart with the utmost care; for out of these are the issues of life,’ (Proverbs 4:23).
In order to remain in vigilance, it is necessary to guard the freshness and brightness of the mind with all care. The mind becomes darkened from imprudent use of food, drink and sleep, from much talking, from distraction and from worldly cares. Attend to yourselves, said the Lord, be on your guard and take care that your hearts are never weighed down, dulled and depressed by self-indulgence, overeating and drinking, or worldly cares and pleasures, lest that day (the day of Christ's dread judgment, the last day of the world) catch you unawares. For it will spring like a trap upon all who are living on the face of the earth. So watch and pray at all times for the strength to escape or survive all that is going to happen, and to stand before the Son of Man.
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.
Everything must be directed towards acquiring the Kingdom of God and fulfilling Christ's Gospel. True Christianity does not consist in intellectual abstract deliberations and teachings; rather, it is incarnate in life itself. Christ descended to earth not to instruct people in new forms of knowledge, but to call them to a new life. During our earthly life we prepare ourselves for eternity.
Smoke from wood kindling a fire troubles the eyes; but then the fire gives them light and gladdens them. Similarly, unceasing attentiveness is irksome; but when, invoked in prayer, Jesus draws near, He illumines the heart; for remembrance of Him confers on us spiritual enlightenment and the highest of all blessings.
The kingdom of God is always present for him who desires and wills it. When a man's disposition and way of life are like that of an angel, most assuredly this is the kingdom of God. For God indeed is said to rule as King when nothing worldly meddles in the governing of our souls and when in every respect we live not of this world. This manner of life we have within us, that is to say, we have it within us when we desire and will it. We do not need to wait a long time, or until our departure from this life; instead, faith and a God-pleasing life which accompanies faith are very near us.
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.
St. Gregory the Dialogist wrote about what price we have to pay to acquire the Kingdom of Heaven. It has no exact price. Everyone has to give everything he has. The Apostle Peter gave his nets & received the heavenly kingdom; the widow gave two mites; whoever has a million dollars, let him give that; & whoever has nothing, let him give his freedom.
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.
The road into the Kingdom of Heaven was made by the Lord Jesus Christ, and He was the first one who traveled it. The Bible teaches that only he who follows Jesus can reach His Kingdom. But how can one follow Him? Hear what our Savior says about this: Whoever desires to come after Me, let him deny himself, and take up his cross, and follow Me (Mark 8:34). The words whoever desires mean that Christ does not compel anyone to follow Him. He has no need of the unwilling ones, but He desires that each person freely follow Him. Consequently, only those who willingly choose the Savior's path reach the Kingdom of Heaven.
In order not to be in daily bondage to the passions and the Devil, you must set yourself an object to aim at, have this object constantly in view, and endeavor to attain it, conquering all obstacles by the name of the Lord. What is this object? The Kingdom of God, the Divine palace of glory, prepared for believers from the creation of the world. But as this object can only be attained by certain means, it also is necessary to have such means at one's disposal. And what are these means? Faith, hope, and love, especially the last. Believe, hope, and love, especially love, disregarding all obstacles; love God above everything and your neighbor as yourself. If you have not sufficient strength to preserve in your heart these inestimable treasures, fall down oftener at the feet of the God of Love. 'Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you' (Matt. 7:7-8) - for He Who has promised is true.
We should zealously cultivate watchfulness, my brethren; and when, our mind purified in Christ Jesus, we are exalted by the vision it confers, we should review our sins and our former life, so that shattered and humbled at the thought of them we may never lose the help of Jesus Christ our God in the invisible battle.
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).
