Man, according to the scriptures, is created “in the image of God”. To be like God, through the gift of God, is the essence of man’s being and life. In the scriptures it says that God breathed into man, the “Breath [or Spirit] of life”. This teaching has given rise to the understanding in the Eastern Church that man cannot be truly human, truly himself, without the Spirit of God. Thus St. Irenaeus (3rd century) said in his well-known saying, that “man if body, soul and Holy Spirit.” This means that for man to fulfill himself as created in the image and unto the likeness of God – that is, to be like Christ Who is the perfect, divine, and uncreated Image of God – man must be the temple of God’s Spirit. (An aside. This is why the Eastern Church always talks about humans being a three-part composite: body, soul and Spirit. It was only in the west where humans were defined as body and soul. This is also why I believe that Freud came up with his tri-part division of the mind: Id, Ego and Superego).
If man is not the temple of God’s Spirit, then the only alternative is that he is the temple of the evil spirit. There is no middle way. Man is either in an unending process of life and growth in union with God by the Holy Spirit, or else he is an unending process of decomposition and death by returning to the dust of nothingness out of which he was formed, by the destructive power of the devil. This is how the Eastern Church’s spiritual tradition interprets the “two ways” of the Mosaic law: “I call heaven and earth to witness… that I have set before you life and death… therefore choose life that you and your descendants may live, loving the Lord, obeying His voice and cleaving to Him, for that means life to you” (Dt 30:19-20).