Remember, O my soul, the terrible and frightful wonder: that your Creator for your sake became Man, and deigned to suffer for the sake of your salvation. His angels tremble, the Cherubim are terrified, the Seraphim are in fear, and all the heavenly powers ceaselessly give praise; and you, unfortunate soul, remain in laziness. At least from this time forth arise and do not put off, my beloved soul, holy repentance, contrition of heart and penance for your sins.
I am a Christian, you say, and content yourself with this. This is the first deceit - transferring to yourself the privileges and promise of Christianity, without any care to root true Christianity into yourself; or to ascribe to yourself that which can only be acquired by your strength and inner worthiness. Explain to yourself that it is illusory to hope in a name, that God can raise a son of Abraham from a stone and can take away your promise at any time if the conditions for participating in them are not soon fulfilled. Mainly, clarify to yourself what it means to be a Christian, unite yourself to this ideal, and you will see just how stable is this buttress to your blindness.
The origin of the Christian life is in arousal by grace. A person who has heeded this arousal is not then deprived of guidance by grace and communion with it at all times, as it persists through proper attention to it.
The day will come when you are toiling at self-observation and self-constraint, and the adversary will come up and mumble in your ear, 'This will all happen eventually. You’ve been working hard, now take it easy a little bit!' This is such a tempting suggestion that it does not immediately occur to you that you should counter it, or that it is so bad that however little you give in to it, it will cause such inner disturbance. Indulging yourself is just like a tiny hole in a dam. Once a hole has formed, the dam cannot hold; the water will inevitably destroy it. Indulgence does the same thing inside of us; everything will be dispersed, so it will be necessary to start all over again to restore ourselves. Fear this as your most evil enemy, although he speaks with the sweetest words.
One must clean the royal house from every impurity and adorn it with every beauty, then the king may enter into it. In a similar way one must cleanse the earth of the heart and uproot the weeds of sin and the passionate deeds and soften it with sorrows and the narrow way of life, sow in it the seed of virtue, water it with lamentation and tears, and only then does the fruit of dispassion and eternal life grow. For the Holy Spirit does not dwell in a man until he has been cleansed from passions of the soul and body. Only one thing may remain within a man, either the Holy Spirit or the passions. Where the Holy Spirit is, there the passions do not come near, and where the passions are, there the Holy Spirit does not dwell, but rather the evil one.
God, the Word, made man for the salvation of our race, aware of the exceeding frailty and misery of our nature, hath not even here suffered our sickness to be without remedy. But like a skillful doctor, he hath mixed for our unsteady and sin loving heart the potion of repentance, prescribing this for the remission of sins. For after we have received the knowledge of the truth, and have been sanctified by water and the Spirit, and cleansed without effort from all sin and all defilement, if we should happen to fall into any transgression, there is, it is true, no second regeneration made within us by the Spirit through baptism in the water of the font, and wholly recreating us (that gift is given once for all); but, by means of painful repentance, hot tears, toils and sweats, there is a purifying and pardoning of our offences through the tender mercy of our God. For the fount of tears is also called baptism, according to the grace of the Master.
The zealous are eager for ascetical struggles of self-forcing and self-opposition with the aim of self-correction, or of raising themselves to primordial purity, so that they might all the more speedily become worthy of communion with God. Obviously the more eager one is, the more diligently and longingly he does this, the sooner he achieves his goal.
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.
As it is not possible to walk without feet or fly without wings, so it is impossible to attain the Kingdom of Heaven without the fulfillment of the commandments.