In Many Religions, One Covenant, Cardinal Joseph Ratzinger spans the deep divides in modern Catholic scholarship to present a compelling biblical theology, modern in its concerns yet classical in its breadth. It is his classical mastery, his ressourcement, that enables the Cardinal to build a bridge.
Cardinal Ratzinger seeks to deepen our understanding of the Bible's most fundamental principle. The covenant defines religion for Christians and Jews. We cannot discern God's design or his will if we do not meditate upon his covenant.
The covenant, then, is the principle that unites the New Testament with the Old, the Scriptures with Tradition, and each of the various branches of theology with all the others. The covenant does more than bridge the gaps between these elements; it fills in the gaps, so that biblical scholarship, dogmatic theology, and magesterial authority all stand on common ground solid ground.