The Mass on the World remains Teilhard's most popular essay. It is a fifteen-page prayer rich in imagery and passion suggesting more than it states. In exploring the careful thought behind Teilhard's images the present work reveals the heart and mind of the man as other approaches have not done. In the Offertory of his Mass Teilhard brought the world's hungers and disappointments into prayer; the Consecration is seen as the consummation of his work in science; while the Communion called him to a life of adventure, of success and sorrow rarely equaled. The Post-Communion tells how Teilhard transformed the simple devotions of childhood into the adoration of maturity. He ends his Mass with a dedication to the apostolate, and starting from this text the present work develops what it means to be an Apostle of Christ in a pluralistic world. Above all, Teilhard was a priest--and under his guidance all Christians can answer their call to priesthood. Teilhard's Mass shows how every Christian can transform one's life and death into an all-embracing Mass on the Altar of the World. +