In Charles Williams Descent into Hell, one of the characters contemplates "a good so alien as to be terrifying." I think that is what Peter Damascene sees. How can being a slave, being sick, or being in subjugation bring about anything good? I can see why some would worry about possible philosophical slight of hand. They wonder, how can evil produce good?
But what if good is much more alien than we suppose? What if turning the other cheek and not resisting evil really is the way to good? It is rather terrifying to take Jesus literally.
This is, I think, part of the reason why the Church needs monastics. Most of us have neither the courage nor the faith to take Jesus at His word. To do so would involve too much suffering. However, in a monastic context, spiritual athletes can be trained--that is literally what the word "asceticism" means. In a monastic context, it is possible--it has indeed been done--to train a man and woman to leave everything and follow Christ. And when they do, their words are terrifying to us. Like Peter Damascene's.
Last Sunday was the Gospel reading of the parable of the Publican and the Pharisee. Like the Publican, my heart trembles at the terrible and alien reality of God's goodness. Like the Publican, all I can do is beat my chest and stand afar off and cry: "Have mercy on me the sinner."