He who stands by a fire is warmed by it, and he who turns to the Lord with his mind and heart is warmed by the fervor of His love, and himself begins to return a warm disposition towards Him...The love of God is shed abroad in our hearts... (Rom. 5:5).
The first duty of a Christian, of a disciple and follower of Jesus Christ, is to deny oneself. To deny oneself means to give up one's bad habits, to root out of the heart all that ties us to the world; not to cherish bad desires and thoughts; to quench and suppress bad thoughts; to avoid occasions of sin; not to do or desire anything from self-love but to do everything out of love for God. To deny oneself means, according to the Apostle Paul, to be dead to sin and the world, but alive to God.
You have the book of discourses by St. Macarius of Egypt. Kindly read the 19th discourse, concerning a Christian's duty to force himself to do good. There it is written, 'One must force oneself to pray, even if one has no spiritual prayer.' And, 'In such a case, God, seeing that a man earnestly is striving, pushing himself against the will of his heart (that is, his thoughts), He grants him true prayer.' By true prayer, St. Macarius means the undistracted, collected, deep prayer that occurs when the mind stands unswervingly before God. As the mind begins to stand firmly before God, it discovers such sweetness, that it wishes to remain in true prayer forever, desiring nothing more.
Our prayer reflects our attitude towards God. He who is careless of salvation has a different attitude toward God from him who has abandoned sin and is zealous for virtue but has not yet entered within himself and works for the Lord only outwardly. Finally, he who has entered within and carries the Lord within himself, standing before Him, has yet another attitude. The first man is negligent in prayer, just as he is negligent in life, and he prays in church and at home merely according to the established custom, without attention or feeling. The second man reads many prayers and goes often to church, trying at the same time to keep his attention from wandering and to experience feelings in accordance with the prayers which are read, although he is seldom successful. The third man, wholly concentrated within, stands with his mind before God, and prays to Him in his heart without distraction, without long verbal prayers, even when standing for a long time at prayer in his home or in church.... Every prayer must come from the heart and any other prayer is no prayer at all. Prayer-book prayers, your own prayers and very short prayers, all must issue forth from the heart to God, seen before you.
Since the enemy watches you constantly, waiting for an opportunity to sow evil in you, be doubly watchful over yourself, lest you fall in the nets spread for you. As soon as he shows you some fault in your neighbor, hasten to repel this thought, lest it take root in you and grow. Cast it out, so that no trace is left in you, and replace it by the thought of the good qualities you know your neighbor to possess, or of those people generally should have. If you still feel the impulse to pass judgment, add to this the truth that you are given no authority for this and that the moment you assume this authority you thereby make yourself worthy of judgment and condemnation, not before powerless men, but before God, the all-powerful Judge of all.
To more conveniently become accustomed to remembering God, the fervent Christian has a special means, namely, to repeat ceaselessly a brief prayer of two or three words. Mostly this is 'Lord, have mercy.' or 'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' If you have not yet heard of this, then hear it now, and if you have not done it, then begin from this hour to do it.
Grow calm, grow quiet after harmful noise... you will experience a certain movement towards eternity; gradually, like a still, small voice, a thought will come to you as to who you are and what is your end and purpose... this is a sign of the approach of the word of God in your soul.
Try to know yourself, your own wickedness. Think on the greatness of God and your wretchedness. Meditate on the suffering of Christ, the magnitude of Whose love and suffering surpass our understanding. Ascribe the good that you do to God alone. Do not think about the sin of a brother but about what in him is better than in yourself.... Flee from glory, honors and praise, but if this is impossible, be sorry that such is your lot. Be benevolent to people of low origin. Be freely and willingly obedient not only to those above you but to those below .... The lowlier we are in spirit, the better we know ourselves, and without humility we cannot see God.
What do we do when attacked by some criminal? We strike out at him and shout for help. Our cries are answered by the police, who then rescue us from danger. We must do the same in inner warfare with the passions. Filled with anger against them, call for assistance: Help me, O Lord! Jesus Christ, Son of God, save me! O God, make speed to save me! O Lord make haste to help me! Having thus called on the Lord, do not allow your attention to wander from Him, do not let it turn to what is happening within you, but go on standing before the Lord and imploring His help. This will make the enemy run away as though pursued by flames.
Set as a goal the kindling of the fire of the spirit, so that the spiritual fire will burn in your heart and, gathering up all your strength into one, will begin to build your inner man and finally burn up the tares of your sins and passions.
The old man was asked, 'What is the good of the fasts and watchings which a man imposes on himself?' and he replied, 'They make the soul humble. For it is written, Consider my affliction and my trouble, and forgive all my sins' (Psalm 25:18). 'So if the soul gives itself all this hardship, God will have mercy on it.' The old man was (also) asked, 'What should a man do in all the temptations and evil thoughts that come upon him?' The old man said to him, 'He should weep and implore the goodness of God to come to his aid, and he will obtain peace if he prays with discernment. For it is written, 'With the Lord on my side I do not fear. What can man do to me?' (Psalm 118:6).
The kingdom of God is within us when God reigns in us, when the soul in its depths confesses God as its master, and is obedient to Him in all its powers. Then God acts within it as master ‘both to will and to do of his good pleasure’ (Phil. ii. 13). This reign begins as soon as we resolve to serve God in our Lord Jesus Christ, by the grace of the Holy Spirit. Then the Christian hands over to God his consciousness and freedom, which comprises the essential substance of our human life, and God accepts the sacrifice; and in this way the alliance of man with God and God with man is achieved, and the covenant with God, which was severed by the fall and continues to be severed by our willful sins, is re-established. This inner alliance is sealed, confirmed, and given the strength to maintain itself by the power of grace in the divine sacrament of baptism, and for those who have fallen after baptism, in the sacrament of repentance: and afterwards it is constantly strengthened by holy communion. All Christians live thus; and consequently they all bear the kingdom of God within themselves, that is to say they obey God as King and are ruled by God as King.