This work, the third in a series, seeks to elucidate the complex and beautiful relationship between Biblical Israel and the Church in God's plan. The Church is viewed as the fulfillment of the Old Testament prophecies of the messianic Kingdom. Themes include: the People of God; the four marks of the Church (one, holy, catholic, and apostolic); the oral Torah and oral Tradition; the universal call to holiness; justification; continuity and discontinuity between Israel and the Church; and Mary, daughter of Zion and Mother of the Church. It is hoped that this book may deepen the awareness of Catholics (and others) of the luminous teaching of the Second Vatican Council in Nostra aetate 4: "The Church cannot forget that . . . she draws sustenance from the root of that well-cultivated olive tree (Israel) onto which have been grafted the wild shoots, the Gentiles."