The Shema Yisrael prayer—“Hear O Israel, the L‑rd is our G‑d, the L‑rd is One”—is perhaps the best-known statement of faith in the Jewish liturgy. They were the last words of millions of Jews as they were massacred at the hands of the Greeks, burned at the stake in Spain and gassed in German extermination camps. The six words of the Hebrew text are the nexus of the Jewish prayer service, morning and night.

But why? What is it about these words, and the concept of divine unity that they proclaim, that encapsulates the essence of Jewish belief?

In a new five-part online course, “The Infinity of One,” Rabbi Yechezkel Kornfeld examines the traditional Jewish understanding of divine unity and man’s relationship with G‑d.

A master teacher with decades of experience as a rabbi in Seattle, Wash., Rabbi Kornfeld was profoundly influenced by the legendary chassidic teacher Rabbi Shlomo Chaim Kesselman of Kfar Chabad, Israel. He also studied at Rabbi Isaac Elchanan Theological Seminary (RIETS), the rabbinical seminary of Yeshiva University.

The five-week course includes video instruction, a wealth of supplementary readings, and quizzes to help monitor the students’ mastery of the material.

For more information and registration, visit the course page at Chabad.org/Infinity.