This dissertation examines Augustine's writings on the relation of temporal activity to eternal contemplation of God. It argues that Augustine resolves this question theologically in Christ with his doctrine of the totus Christus, L558the whole Christ with Christ as Head and the Church as Body, teaching that Christ united himself to all of humanity in order to transform humanity into his Body, the Church. Reading a selection of Augstine's works, primarily his sermons, through the lens of the doctrine of the totus Christus reveals that the present life holds great value for him because the transformation of the totus Christus reaches to all of life, giving the doctrine a profoundly sacramental dimension. Having been transformed into members of Christ's Body in the sacraments of the Church, Christians participate in Christ's life, being conformed more fully to Christ by sharing in his love. Contemplation breaks into present activity as Christians know God by sharing in God's love, a vision of God that begins in the present and will culminate in eternity. Chapter 1 traces the development of Augustine's thought on action and contemplation showing that as he matures, he comes to understand action and contemplation as two phases of life, the present and the future, for each Christian and the Church as a whole. Chapter 2 introduces Augustine's doctrine of the totus Christus, explaining that Christ serves as the meeting point of the two lives of action and contemplation as he transforms the Church into his Body. Chapter 3 considers the sacramental dimension this transformation gives to the totus Christus, a transformation that brings individual Christians into the unity of Christ and the Church through the sacraments and activity in the world. Chapter 4 concludes the dissertation by describing the value Christ's love gives to daily life as it becomes a place for meeting Christ as well as the matrix for ongoing conformation to Christ as the Church joins his work of love. Christ unites action and contemplation by bringing union with God into the present life of the Church where the promise of vision begins to be fulfilled in love.