Reiner is an articulate spokesman for social justice and the Reform tradition of Judaism, and for good reason: He has spent his whole life thinking about it. Reiner grew up in a Reform family in Chicago, surrounded by a mostly Conservative Jewish community. After graduating from the University of California at Berkeley, he studied to become a rabbi at Hebrew Union College in Cincinnati. After serving congregations in Topeka, Kan., and Chicago, he and his wife arrived at Temple Sinai in Northwest D.C., where Reiner was senior rabbi for 25 years until his retirement in 2010. His new book, “Standing at Sinai: Sermons and Writings,” offers snapshots of those 25 years of thought and scholarship.