Simeon Maslin, 90, of Philadelphia, senior rabbi emeritus at Reform Congregation Keneseth Israel in Elkins Park, former president of the Central Conference of American Rabbis, and an influential author and speaker on Jewish life, died Jan. 29, at home.

As senior rabbi at Keneseth Israel from 1980 to 1997, Rabbi Maslink spoke often and wrote extensively about his faith and its collision with modern issues. A teacher and mentor to many in the United States, Australia, South Africa, Latin America, and elsewhere, he lectured about the importance of religious diversity in communities, the essential role of women in modern life, world peace, the separation of church and state, and other topics.

He called himself a “religious naturalist,” described God as a “guiding friend,” and published a number of books about leading a Jewish life. “The function of a Jew is to be cocreator, with God, of the world. The task of the human being is to perfect the world, using the tools God gives us,” he said.