The patristic tradition, as well as contemporary psychology, has identified the restraints to perfect love. From an Orthodox perspective, if love is union with God, and the pursuit of love is the acquisition of the Holy Spirit then those things that separate us from God – sin, the passions, death, and the devil all represent restraints to perfect love.
Our own self centered, egocentric orientation, our fallen nature represent the biggest restraints to love. “When we speak of all the passions together, we call them ‘the world.’ So when Christians speak of renouncing the world, they mean renouncing the passions.”
(Philip Mamalakis, “The Spiritual Life and How to be Married in it,” Raising Lazarus, p. 223)