Nowhere is the universal call to holiness, the call to live in and embrace the grace of God radically, more fully and challengingly expressed than in this section of Cassian's 21st Conference. These realities become extremely personal as they are displayed through the story of the conversion of Theonas, the elder of the conference. The pursuit of the perfection of grace touches every aspect of life and whether a person is a monk, a virgin or married, they are called to take it up whatever the costs. Theonas was married and comes to the realization that he must embrace more than a lawful commitment to his spouse but a relationship that fosters chastity. The locus of conflict that he begins to identify is between sexual habit and continence in the heart and that it is possible for a person not to be a lover of marriage but rather of slave of lust. Sexuality here becomes the perfect mirror of the human self - the lens through which we see the contortions and distortions of human motivations. He and his wife had been pushed into marriage with the notion that the vows alone would control sexual passions. They mistakenly thought that purity of heart could be fostered without embracing fully the life of grace and its expression in a disciplined life. Marriage is touched by grace - it is to make present the selfless love of Christ for his Bride the Church. This comes at a costs and by grace, not by magic or wishful thinking.