This work by Nicholas Cabasilas is a remarkable product of Byzantium's last great flowering of theology. At a time when secular humanism was increasingly asserting man's complete autonomy, Cabasilas proclaimed that man's true life lies not in himself, but in Christ. For him, man's redemption in Jesus Christ is not just a matter of history, which can be elucidated simply by scholarly endeavor; it is a saving event in which man is called to participate here and now, in body and spirit as well as intellect, through the sacramental life of the Church. The present translation makes this devotional classic available for the first time in English, while the extensive introduction by Boris Bobrinskoy assesses its place within the history of eastern spirituality.