When a gunman slaughtered 11 worshipers in a Pittsburgh synagogue on a Shabbat morning last month, American Jews were left with a jumble of intense emotions: horror and fear, certainly, but also an old embattled feeling, centuries in the making. They were victims, in America, a country that has never seen even a hint of a pogrom. In their pain and worry, individual Jews had a rare chance to feel themselves part of a larger community — one that mourns together, gets angry together, imbued with a separate and unique identity, threatened yet resilient. And in this, victimhood offered an illusion.

For one thing, the violence of Pittsburgh is far from the everyday reality of American Jews. They live in a country that has offered them a great deal more love than it ever has hate. We’re beyond mere tolerance. A recent Pew poll found that Americans felt “warmer” about Jews than any other religious group. There is an accumulated sense of comfort and acceptance that has persisted even with a president whose winks have emboldened thousands of internet trolls and hundreds of white men bearing tiki torches. The positive side of the ledger remains plentiful.

A shared sorrow may have provided the briefest taste of unity after Pittsburgh, but anti-Semitism is not what defines the experience of Jews in America today; assimilation is. To hear the professional worriers in the Jewish community, it’s love, not hate, that poses the bigger existential challenge. A vast majority of Jews — 72 percent among the non-Orthodox — now marry outside the tribe. The infrastructure of Judaism, from the synagogue to the long-established liberal denominations, is being steadily abandoned. Almost a third of millennial Jews are so unidentified with Judaism they say they have no religion at all. And Israel, which once inspired, now alienates many, especially the young. Even the massacre in Pittsburgh, for those who knew where to look, offered hints of this demise. The average age of the victims, those mainstays who turned on the lights and made sure the grape juice and cookies were set up for the kiddush, was 74. Three congregations gathered in one synagogue that morning because of dwindling numbers.

Once the candlelight vigils are over, where is the solid ground for the future of American Jewish identity? It won’t come from being victims — it shouldn’t — and cultural and ethnic identity, the bagels and lox version, is disappearing fast. From where then? As a handful of new books make abundantly clear, there really is only one source left: the religion — Judaism itself, and its unique capacity for adaptation.