In A Jewish Jesuit in the Eastern Mediterranean, Robert Clines retraces the conversion and missionary career of Giovanni Battista Eliano, the only Jewish-born member of the Society of Jesus. He highlights the lived experience of conversion, and how converts dealt with others' skepticism of their motives. Clines uses primary sources, including Eliano's personal letters, missionary reports, and autobiography, together with scholarship on conversion in the early modern Mediterranean world to illustrate how false and sincere conversion often mirrored each other in outward performance. Devout converts were not readily taken at face value and needed to prove themselves in the moment and over the course of their lifetimes. Consequently, Eliano's story underscores that the mystical, introspective nature of religious belief and the formulation of new spiritual selves came into direct confrontation with the ways in which converts needed to present themselves to others in an age of political and religious turmoil.