Rabbi Neil Gillman, a Jewish theologian who gave aspiring rabbis and congregants in the Conservative movement new ways to talk about God, death and the afterlife, and who was an important advocate for the movement’s ordination of women and gays, died on Nov. 24 at his home in Manhattan. He was 84.

His daughter Abigail Gillman confirmed the death and said he had been treated for cancer.

Rabbi Gillman, a professor of Jewish philosophy at the Jewish Theological Seminary in Manhattan for 46 years and dean of its rabbinical school for 10, began publishing his writings in the 1980s. At the time, the centrist Conservative movement was struggling with identity and appeal, wondering if its adherents were merely stopping over on their way to becoming barely observant Jews whose allegiance was largely ethnic rather than religious.

It was a movement, he said, in a comment sometimes attributed to others, that consisted of “an Orthodox faculty teaching Conservative rabbis to minister to Reform Jews.”

His ideas helped two generations of rabbis as well as teachers and scholars define their enigmatic ideas about God and faith. They also shaped the movement’s approach to Jewish law and beliefs.

Rabbi Gillman’s breakthrough for thinking about divinity began with his notion of a “second naïveté.” Children conceive of God as perhaps a giant bearded figure in the sky, and Rabbi Gillman wanted his listeners to find ways “to rediscover that innocent sense of awe and wonder,” but in ways that made sense to them as adults, said Rabbi Julie Schonfeld, chief executive of the Rabbinical Assembly, the movement’s rabbinic arm.

The path toward understanding God in more personal terms can be found in biblical stories, or “myths,” Rabbi Gillman wrote. In Genesis, for example, Abraham argues with a wrathful but undecided God about how many righteous inhabitants it would take to save the wicked populace of Sodom and Gomorrah from divine annihilation.

“Consider the image of God portrayed in this story,” Rabbi Gillman wrote. “God deliberates, is conflicted, has feelings, invites consultation, is willing to change the divine plan, is open to negotiation and needs to be true to previous commitments. Above all, God has an intense relationship with an individual human being.”

That was an existentialist conception that many rabbinical students could grapple with. Whether the Bible stories were historically factual, he said, was less important than the values they conveyed.

Rabbi Ira Stone, the rabbi emeritus at Temple Beth Zion-Beth Israel in Philadelphia, said in an interview that “students came to the seminary because they were searching for religious meaning, and Neil was the one who took that challenge seriously.”

Rabbi Gillman’s book “Sacred Fragments: Recovering Theology for the Modern Jew” (1990) won the National Jewish Book Award for Jewish thought.

In the 1970s, when the Conservative movement began debating whether to expand women’s roles, he clashed with more traditionalist colleagues and championed a broader vision, including ordination to the rabbinate. The seminary faculty approved women’s ordination in 1983 and ordained its first female rabbi two years later.

He also argued for the ordination of gay, bisexual and lesbian rabbis, which the movement approved in 2006. Same-sex marriage ceremonies were approved in 2012, with the caveat that the marriages do not carry the status of kiddushin, which consecrates a marriage between a bridegroom and a bride “according to the laws of Moses and Israel.”

Rabbi Gillman, a genial man recognizable by his goatee and tufts of white hair, often puffed or chomped on a pipe as he threw ideas around with students in an office crammed with towers of books. Those ideas also reached beyond rabbinical circles to lay people through frequent talks he gave at synagogues — Reform and Reconstructionist as well as Conservative — on so-called scholar-in-residence weekends.

In his book “The Death of Death: Resurrection and Immortality in Jewish Thought” (1997), Rabbi Gillman chronicled the evolution of Jewish ideas on death and the afterlife. He pointed out that in daily prayers God is praised for reviving the dead and that in the song that concludes the Passover Seder, “Chad Gadya,” the Angel of Death is killed by God. Therefore, he said, resurrection, including bodily resurrection, is a concept Jews should be wrestling with.

“Not that he believed in literal resurrection,” Rabbi Stone said. “What he believed was that the myth contained profound truth. The body was as holy as the soul. And a philosophy that focused on human beings as disembodied beings ultimately was false. The body is sacred, is a temple. Human beings exist body and soul.”

Neil Gillman was born on Sept. 11, 1933, in Quebec City, which at the time had a community of roughly 120 Jewish families with no yeshiva and no kosher butcher. His father, Ernest, an immigrant from Russia, took over his father-in-law’s clothing factory, and his mother, Rebecca, was the bookkeeper. Young Neil was greatly influenced by his immigrant grandmother, Devorah Gardner, and her commitment to keeping Jewish customs.

He majored in philosophy and French literature at McGill University in Montreal and there heard Will Herberg, a sociologist of religion, speak about Jewish philosophy.

“It was a life-changing encounter,” Abigail Gillman said.

Rabbi Gillman decided to pursue the subject but was advised to first ground himself in Jewish texts. At the Jewish Theological Seminary, he was influenced by the towering intellectuals Mordecai Kaplan and Abraham Joshua Heschel.

He was ordained in 1960 and soon teaching seminary students. Simultaneously, he studied secular philosophy at nearby Columbia University, receiving his doctorate in 1975.

In addition to his daughter Abigail, Rabbi Gillman is survived by his wife, Sarah Fisher Gillman; another daughter, Deborah Gillman; a sister, Betsy Friedman; and five grandchildren.