The change from a life in which the heart is directed (tyrannized and imprisoned) to one in which the heart directs (set free to direct) is another way of saying “salvation.” It is the change from a life that is really death and death-giving to a life that is really life and life-giving. For, indeed, the heart is the center of human being.
When we recognize and accept the dignity of our human nature in Christ Jesus we can enter into a right relationship with all things. The end of delusion and ignorance. The restoration of sight – comprehending and knowledge – of the truth of all things; the form and shape of our right relationship with them is illumination. This illumination is fulfilled, through repentance in all of its forms, in our deification.
Our Lord Jesus Christ, born true man without ever ceasing to be true God, began in his person a new creation and by the manner of his birth gave man a spiritual origin. What mind can grasp this mystery, what tongue can fittingly recount this gift of love? Guilt becomes innocence, old becomes new, strangers are adopted and outsiders are made heirs. Rouse yourself, man, and recognise the dignity of your nature. Remember that you were made in God’s image; though corrupted in Adam, that image has been restored in Christ.
Use creatures as they should be used: the earth, the sea, the sky, the air, the springs and rivers. Give praise and glory to their Creator for all that you find beautiful and wonderful in them. See with your bodily eyes the light that shines on earth, but embrace with your whole soul and all your affections the true light which enlightens every man who comes into this world. Speaking of this light the prophet said: Draw close to him and let his light shine upon you and your face will not blush with shame. If we are indeed the temple of God and if the Spirit of God lives in us, then what every believer has within himself is greater than what he admires in the skies.
Our words and exhortations are not intended to make you disdain God’s works or think there is anything contrary to your faith in creation, for the good God has himself made all things good. What we do ask is that you use reasonably and with moderation all the marvellous creatures which adorn this world; as the Apostle says: The things that are seen are transient but the things that are unseen are eternal.
For we are born in the present only to be reborn in the future. Our attachment, therefore, should not be to the transitory; instead, we must be intent upon the eternal. Let us think of how divine grace has transformed our earthly natures so that we may contemplate more closely our heavenly hope. We hear the Apostle say: You are dead and your life is hidden with Christ in God. But when Christ your life appears, then you will also appear in glory with him, who lives and reigns with the Father and the Holy Spirit for ever and ever. Amen. Source: From a sermon by Saint Leo the Great