My study concerns the teacher knowledge of "mehankhim," teachers in Israeli high schools entrusted to promote students' moral, civic, and social growth. It examines two "mehankhim" from a secular Israeli high school who participated in a long-term professional development program in secular Jewish education, centered by traditional and modern Jewish texts. This study is situated within the body of research on teachers' professional development, focusing on the vocation of "mehanekh" in secular Jewish education, teachers' professional knowledge, and "mehankhim's" life stories. I suggest that "mehankhim" are professionals, with a professional practical knowledge unique to them, despite their current lack of specific training for their vocation. One major source of knowledge that informs the practice of today's "mehankhim" is the historical legacy of the role. A second is the evolution of Israeli public discourse, which demands a corresponding evolution in the undefined "mission statement" of "mehankhim," and in their preparation and in-service training. Using the qualitative method of portraiture and relying on narrative analysis, I have drawn portraits of two "mehankhim." I completed a full ethnographic survey of the participants in their professional setting, engendering the creation of a multi-layered, comprehensive and esthetic whole. This study examines ways to professionalize the vocation of "mehankhim." It offers hope for change in the Israeli public discourse by well-trained Jewish and Arab "mehankhim," invigorated with a new popular mandate; it suggests an opportunity for Jewish Israeli "mehankhim" to collaborate with their American counterparts in Jewish education, giving Jewish texts a central role. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]