NEW YORK — As the High Holy Days approach, rabbis in the United States say their congregations are deeply unsettled by antisemitic threats and aware of sharp divisions in their own communities. But many are also determined to embrace the coming days of celebration and reflection.“Jews feel extremely precarious right now,” said Rabbi David Ingber, founder and spiritual leader of Romemu, a fast-growing, nondenominational Jewish congregation in New York City.Ingber says many of his congregants are politically liberal and opposed to Israel’s policies on Gaza and other issues, yet are troubled by vehement assertions that Israel has no right to exist as...