What is sin?
It is the narrow, temporal, pursuit of pleasure, significance, and security, without and against our good Creator and Father
In his analysis of Athanasius' Contra Gentes, Thomas Weinandy's makes some perceptive comments about sin and desire. Listen to the notes that he strikes...pleasure, anxiety, security, temporality, delusion:
Sin, for Athanasius, is the turning away from God and all that pertains to him and a lustful self-centred turning inward to what pertains to man and his earthly bodily life with all its sensual pleasures. Sadly, human beings became 'habituated to these desires, so that they were afraid to leave them' (Contra Gentes, 3.4). Thus the soul anxiously feared death for in death all bodily lust and pleasures ceased. (Athanasius: A Theological Introduction, p. 15)
For sin, to Athanasius' mind, is more than a turning toward and seeking after the sensuous things of the world; rather these are but symptoms of human beings being more concerned about themselves than they are about God. (p. 17)