JERUSALEM — On July 21, a young Israeli woman posted an account on Facebook about falling in love with another woman. The young woman comes from a modern-Orthodox Jewish family. She had been hoping to have a traditional Orthodox family life — a husband and several children living in a community adhering to Jewish law. Yet after a decade of searching for love, she ended up finding it where she least expected. Her true love came tangled up with the heartbreaking realization that everything she was hoping for — the husband, the children, the community — was not going to happen the way she envisioned it.

That young woman is my sister.

She is usually a private person, not the type who would casually present her story for everyone — including our parents’ Orthodox friends — to see. But this time she had a reason. “These days it is clearer than ever that the personal, at least this kind of personal, is very much political,” she wrote. To put it even more plainly, her reason has a name: Rabbi Yigal Levenstein.

Ten days before my sister’s Facebook post, Rabbi Levenstein publicly condemned an atmosphere that celebrated what he described as L.G.B.T. “perverts.” Rabbi Levenstein probably thought he was drawing a line in the sand against the inroads the L.G.B.T. community was making in Israel. But he ended up igniting something quite remarkable: the largest gay pride parade ever in Jerusalem, in which a significant number of modern-Orthodox Israelis showed their support by marching.

Orthodox Judaism adheres to a strict biblical ban on homosexuality. Israel’s modern-Orthodox branch, known as Zionist-Orthodox, accounts for about 14 percent of the Jewish population and is usually counted as one of the four main branches of Israeli Judaism: secular, traditional, Zionist-Orthodox and ultra-Orthodox. Modern-Orthodox adherents try to live a strict Jewish life without separating themselves from the modern world — a world that is more open-minded about homosexuality. Israel is a Jewish state in which Orthodox rabbis are often the official interpreters of Judaism. Israel is also a country in which acceptance of homosexuals is high (with some issues, admittedly, still under debate).