Saint Isaac of Syria was an ascetic, a mountain solitary, but his writings are universal in scope. They are addressed not just to the desert but to the city, not just to monastics but to all the baptized. With sharp vividness he speaks about themes relevant to every Christian: about repentance and humility, about prayer in its many forms, both outer and inner, about solitude and community, about silence, wonder, and ecstasy. Along with the emphasis that he places upon "luminous love"-to use his own phrase-two things above all mark his spiritual theology: his sense of God as living mystery; and his warm devotion to the Saviour Christ.