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.
As earth thrown over it extinguishes a fire burning in a stove, so worldly cares and every kind of attachment to something, however small and insignificant, destroy the warmth of the heart which was there at first.
The Christian ought not to be of doubtful mind, nor by anything drawn away from the recollection of God and of His purposes and judgments. The Christian ought in all things to become superior to the righteousness existing under the law, and neither swear nor lie. The Christian ought to be patient, whatever he has to suffer, and to convict the wrong-doer in season, not with the desire of his own vindication, but of his brother's reformation, according to the commandment of the Lord.
In the heart is the will; in the heart is love; in the heart is the mind--in the heart is the image of the divine Trinity. The heart is the home of the Father, the altar of the Son and the workshop of the Holy Spirit. God wants our hearts: Son, give Me thy heart. Oh, my brother, above and beyond all else that you keep safe, guard your heart. Let the mountains be overthrown and the seas dried up; let friends forsake you and riches betray you; let your body be eaten by worms; let the world pour on you all the scorn of which it is capable--and do not fear. Only guard your heart; guard it and make it cleave to the Lord; give it into His keeping. Life flows from the heart; but whence comes this life in the heart, unless it is the abode of the breath of the Lord and Source of life-God? Oh, my brother, the Spirit of God Himself can, when He so desires, dwell in the human heart. He not only can, but wills to do so. Only, He waits for you to prepare your heart for Him; to make it into a temple, for God the Holy Spirit only lives in a temple. As a snake protects its head, so, my son, guard your heart. For the life that comes from the living God enters into it and flows forth from it.
If some Christians cannot comprehend our Orthodox faith, its Sacraments, it proves that the minds and hearts of such persons are too impure and passionate to bear its purity and brightness, just as sick eyes cannot bear the light of the sun. This heavenly treasure can only be comprehended by the hearts of those who free their minds and feelings from worldly attachments.
St. John Climacus was asked if there are reliable signs by which it's possible to know whether a soul is drawing near to God or moving away from Him. After all, regarding ordinary things there are clear signs as to whether they're good or not. When, for instance, cabbage, meat or fish begins to rot, it's easy to notice it, since the rotting object begins to give off a foul odor, the color and taste change, and its external appearance witnesses to its deterioration. Well, and what about the soul? After all, it's bodiless and can't give off a bad smell or change its appearance. To this question the Holy Father replies, 'A sure sign of the deadening of the soul is the avoidance of church services.'
Prayer offered up at night possesses a great power, more so than the prayer of the day-time. Therefore all the righteous prayed during the night, while combating the heaviness of the body and the sweetness of sleep and repelling bodily nature.
The designation of a Christian consists in glorifying the Heavenly Father by one's life. Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven (Matt. 5:16). But true glorification of God is possible only if one rightly believes and expresses his right belief in words and deeds.
Not every man is wakened to wonder by what is said spiritually and has great power concealed in it. A word concerning virtue has need of a heart unbusied with the earth and its converse.
Intemperance and attachment to things cause torrents of passions to flood the soil of the heart and deposit there all the mud and filth of thoughts, thus confusing the mind, darkening the heart and weighing down the body. In the heart and the soul they produce negligence, darkness and death and deprive them of the feeling and disposition natural to them.
According to the teaching of the Fathers, any impression which, touching the heart, fills it with a great irritation, must come from the region of passions. Therefore impulses which spring from the heart should not be followed at once, but only after careful examination and fervent prayer. God preserve us from a blind heart! It is well known that passions do blind the heart and screen the shining sun of the mind that we should all strive to gaze at.
A true Christian is made by faith and love toward Christ. Our sins do not in the least hinder our Christianity, according to the word of the Savior Himself. He deigned to say: not the righteous have I come to call, but sinners to salvation; there is more joy in heaven over one who repents then over ninety righteous ones. Likewise concerning the sinful woman who touched His feet, He deigned to say to the Pharisee Simon: to one who has love, a great debt is forgiven, but from one who has no love, even a small debt will be demanded. From these judgments a Christian should bring himself to hope and joy, and not in the least accept an inflicted despair. Here one needs the shield of faith.