For over half a century Rabbi Arthur Green has taught Jewish mysticism, Hasidism and theology. He recently noticed a new trend. “Young people are asking a question that was never asked in my generation. They are asking, ‘Why be Jewish?’” said Green, who has taught at the University of Pennsylvania, the Reconstructionist Rabbinical College, Brandeis University and Hebrew College.

To answer that question, the preeminent authority on Jewish thought and spirituality and author of more than a dozen books wrote “Judaism’s 10 Best Ideas: A Brief Guide to Seekers.”

“I write for people who think they don’t have a home in Judaism,” Green said. “I want to show them that they do, that there is something interesting and spiritually fascinating and attractive about this tradition.”

The 100-page pocket-book reveals Rabbi Green’s personal understanding of Jewish tradition, based on his experiences teaching, studying and translating sacred texts. Ten chapters address the core tenets of Jewish life, such as simcha (joy), tikkun olam (repair the world) and Talmud (education) in a style that combines warmth and humor with practical applications for contemporary life. “Shabbat — Getting Off the Treadmill,” for example, offers ten pathways toward a new Shabbat with five “to do’s” and five “not to do’s.”

“In this day of freer choices of identity, I want to show people that Judaism is an important tradition that still has something to say to the world.

I believe we have things to teach the world and that the best years of this tradition are ahead of us, not behind us. I’m an advocate, and that’s what this book is about,” said Green.

At Hebrew College’s Rabbinical School, which he founded in 2004 and where he is Rector, ten percent of the rabbinical students are converts to Judaism. “These Jews by choice are among the most serious and dedicated future rabbis we have,” said Green. “One part of the audience for this book is people who are considering conversion to Judaism.”

Green believes in opening the gate to Judaism and welcoming people who are seeking a spiritual path, whether they are Jewish or non-Jews. “This book is a door-opener,” explained Green.

In the course of his teaching and lecturing, he also met people who told him they didn’t believe in God but somehow believed in a soul and wanted to have an inner life. “They thought they had no home in the Jewish community because they didn’t believe in God. They found themselves attracted to spirituality through one Eastern teaching or another because Eastern teachers didn’t say, ‘You have to believe first.’ These too are precisely the people I am writing to,” said Green.

Although raised in a nonobservant home (“my father was a militant atheist,” he has said), Green found himself drawn to spiritual language after he read “God in Search of Man” by Rabbi Abraham Joshua Heschel as a high school senior. When he was 16 and a freshman at Brandeis University, he became interested in Kabbalah (Jewish mysticism which originated in Hasidic Judaism) after he heard Zalman Schachter, a leading Hasidic Rabbi, Kabbalist and founder of the Jewish Renewal Movement, speak at a campus event. “He impressed me tremendously,” Green said.

Green eventually founded Havurat Shalom, an egalitarian Jewish community in Somerville in 1968, and remains a leading independent figure in the Jewish Renewal Movement.

Although Green no longer teaches at Brandeis University, his connection to the institution spanned many generations. He attended as an undergraduate (B.A. 1961) and graduate student (Ph.D. 1975), and taught there from 1994 until 2004. He thinks of Brandeis as engaged in a continued struggle with its Jewish identity. “Brandeis positions itself as an American university. In its very short history, it has achieved a remarkable reputation as a leading American university, but with one difference: most of its support comes from the Jewish community. Does that make it in any sense a Jewish institution, and what might that mean?” he questioned. This is a question, he said, that Brandeis has struggled with throughout its history.

Despite Green’s busy teaching, writing and lecturing schedule, he does make free time for himself. “I have a mystery life as an antique collector of early American glass,” he confided. “There’s a group of people out there who only know me as Art Green, the glass guy from Boston. They have no idea that I do anything else. I’m happy to have a second identity. I treasure that.”