A first edition of Joseph Samuel C. F. Frey's 1840 book, Judah and Israel: Or, The Restoration and Conversion of the Jews and the Ten Tribes provides a comprehensive view into 19th-century evangelical thought on Jewish-Christian relations and eschatology, particularly concerning the eventual restoration of the Jewish people.

As a German-born converted Jew turned Christian missionary, Frey argues for the future restoration of the Jewish people to their homeland in fulfillment of biblical prophecies. This was a major theological topic in 19th-century Protestantism that helped shape Christian attitudes towards the Jewish people.

Frey founded several missionary societies, including the London Society for Promoting Christianity amongst the Jews (1809) and the American Society for Meliorating the Condition of the Jews (1820). Judah and Israel was part of a larger, controversial body of work that called for the evangelization of Jews. The book delves into the theological implications of this work and the role Frey believed the Christian church should play.

While a controversial figure, Frey is also recognized as an important, pioneering figure in the history of Messianic Judaism, which seeks to integrate Jewish traditions with belief in Jesus. His theological imagination and effort to pioneer a new form of engagement with the Jewish people anticipated aspects of the modern Messianic Jewish movement.