St. Macarius of Egypt: What kind of change Christ works in the Christian

He that comes to God, and desires to be the person that sitteth with Christ upon his throne, ought to come to him upon this very view, that he may be changed from his former state and conversation; that he may be a new man, who carries nothing of the old man about him: “For if any man be in Christ, he is a new creature.” For our Lord Jesus Christ came for this very reason, that he might change, renew, and create afresh this soul that had been perverted by vile affections, tempering it with his own divine Spirit. He came to work a new mind, and a new soul, and new eyes, new ears, a new spiritual tongue; yea, to make them that believe in him new men, that he might pour into them the new wine, which is his Spirit.

For as the enemy, when he had gotten man into his own hands, wrought him anew for himself, having clothed him with vile affections, and poured into him the spirit of sin; so also the Lord, having redeemed him from the enemy, wrought him anew, and poured his own Spirit into him. For he that changed the nature of the burning fire to bedew them that were in the furnace, and for Daniel’s sake tamed the nature of the lions, can also transform the soul that was grown wild by sin into his own goodness and peace by the Holy Spirit of promise.

For as the shepherd can heal a diseased sheep and keep him from the wolves, so the true Shepherd is able to heal the sheep that was lost, even man from the leprosy of sin. The priests and Levites, and the teachers that were before, were never able to heal the soul by their oblations of gifts and sacrifices; yea, they were not able to heal themselves. “For it was not possible that the blood of bulls and of goats should take away sin.” But the Lord can heal every disease, and every sickness of the soul. And the true healing of the soul is from the Lord only.
The good shepherd therefore healeth the sheep. But the sheep itself can never heal the sheep. And unless man be healed, there is no entrance for him into the congregation of the Lord in heaven. Thus also was it said in the law through a shadow: “A leper shall not enter into the congregation of the Lord.” But he commanded the leper to go to the priest, who was to bring him into the house of his tabernacle, put his hands upon the leprosy, the place marked with the infection, and heal it. After the same manner, Christ, the true high priest of good things to come, in condescension to leprous souls, enters into the tabernacle of their body, takes care of their disorders, and healeth them. And thus will the soul be able to enter into the heavenly church of the saints of the true Israel. But every soul that bears the leprosy of sin in her affections, and will not come to the true high-priest and be taken care of now, finds no admission into the camp of the saints. It behoves therefore the soul that truly believeth in Christ, to be changed from her present nature into another nature, which is divine, and to be wrought new herself through the power of the Holy Spirit. And to obtain this, will be allowed to us who believe and love him in truth, and walk in all his holy commandments.

No man can of himself go over the sea unless he have a vessel, which is able to go upon the waters; after the same manner is it impossible for the soul to pass over the sea of sin, and the abyss of the powers of darkness unless it receive the Spirit of Christ that walks, and makes its way over all wickedness, by means of which he will arrive by a quick and straight passage at the heavenly port of rest.

But as a ship stands in need of a pilot, in order to sail well; the Lord himself is a pilot to the faithful soul, and conveys it through all the waves of wickedness, and the strong winds of sin, without Christ, it is impossible for any one to get over the wicked sea of the powers, of darkness. “They mount up”, says the Psalmist, “to the heavens, and go down again to the depths.” But he is well acquainted with the whole art of a pilot, and tramples upon their fierce waves. For he, says the apostle, “Having himself been tempted, is able to succour them that are tempted.”

We ought therefore to believe with our whole heart his unspeakable promises, to love the Lord, and to be industrious in all virtues, and to beg continually, that we may receive the promise of his Spirit entirely and perfectly; that so our souls might be quickened whilst we are yet in the flesh. For unless the soul shall in this world receive the sanctification of the Spirit through much faith and prayer, and be made partaker of the divine nature (through which it will be able without blame and in purity to per form every commandment), it is unfit for the kingdom of heaven. For whatever good a man has possessed in this world, the same shall in that day be his life, through the Father, and the Son, and the Holy Spirit for ever! Amen.

http://www.monachos.net/content/patristics/patristictexts/181-macarius-homilies-12-22