Pesach Sheni is one of those dates in the Jewish calendar that pass most of us by with barely a thought. Its origins lie in a passage in Numbers that appeared in the sidrah a fortnight ago in which a group of Israelites were unable to partake of the paschal sacrifice because of ritual impurity. So they asked Moses for another chance to celebrate — hence a “second Pesach” the following month.

But Iyar 14 has assumed a new significance in Israel (and beyond) as a day to advocate for the inclusion of those who feel marginalised, specifically LGBT Jews.

The emergence of Pesach Sheni is part of a wider campaign by Orthodox LGBT Jews to gain acceptance and recognition within their community (in a country whose new Jewish Identity Authority is to be headed by the leader of an avowedly homophobic party, Noam).

Their struggle for recognition in Israel is documented in an at times eye-opening new book, Queer Judaism, by Orit Avishai , professor of sociology and women’s, gender and sexuality studies at Fordham University, New York.

It is a struggle that pits “liberal” Orthodox rabbis, as the author dubs them, who are sympathetic to LGBT Jews, against the “conservative” rabbis who believe any concession represents a threat to traditional Judaism.

There are a few sections in the book when Professor Avishai’s language reminds you she is an academic, particularly in the introduction’s discussion of queer politics.

But most of the book is an easily read account of her field studies when she reports the often moving stories and experiences of LGBT Orthodox Jews.

Not so long ago they faced a choice of either suppressing their true identity or leaving Orthodoxy. Or they could turn to the now largely discredited conversion therapy in an effort to conform to a heterosexual “norm”. Same-sex attraction was widely seen as a choice, not part of a person’s nature.

According to Rav Moshe Feinstein, the influential 20th-century American authority, same-sex desire was “a deviation from the path of nature”. A conservative Israel rabbi quoted by Professor Avishai opined: “There is no such thing as a religious homosexual.”

As Ariel, one of her interviewees tells her, such ways of thinking have been “deeply entrenched. You are bad, sinful, deviant. There is no place for you. So the question is, how do you rewrite that narrative.”

Some have been expelled from yeshivot after their orientation became known.

One man said his family “didn’t sit shivah but it wasn’t far from that”. Another recalled his brother saying around the Shabbat table, “Letting them get married is like letting someone marry their dog.”

But against these tales of rejection, there has been a gradual shift within Orthodoxy, from viewing LGBT Jews through “the lens of transgression” to a “theology of tolerance”.

While that might represent progress, for many it is not enough, for it still leaves intact the expectation that gay people, if they want to conform to halachah, should condemn themselves to a life of lonely celibacy..

Instead, new organisations such as the umbrella group Kadag, “the proud religious community”, are pushing for rabbis to extend the boundaries of understanding.

Kadag promotes “monogamy, marriage, a family and a home within the community,” Professor Avishai explains.

She quote a number of people who want to lead an Orthodox lifestyle in a community where they can be themselves, praying in an Orthodox synagogue and sending their children to Orthodox schools.

They are not looking to undermine the Jewish home, one activist emphasises. “All we want is a room of own within the Jewish house.”

Daniel, the leader of another organisation Havruta, said at a Pesach Sheni event, “If I stop defining myself as Orthodox, we will allow the Orthodox community to say what used to be true, ‘that [LGBT persons] don’t exist here’.”

As for people who will point to the ban on inter-male penetrative sex in Leviticus, one man counters, “Rabbis don’t enter straight couples’ bedroom, why enter mine?”

As one sympathetic rabbi, Yuval Chernow, has said, “The hard question is not what is forbidden, but what is permissible.”

Avishai also cites another liberal-minded rabbi, Benny Lau (who was once a Bnei Akiva shaliach in the UK), who declared, “The closet is death.”

Three years ago, he published guidelines which stated that same-sex couples could create a “responsible, committed family unit” and there was nothing in halachah that prohibited them from raising a family.

While Orthodox law did not have a solution for same-sex marriage, “there is no reason to deny or renounce a child’s same-sex relationship”.

He added that even if such a couple were living together, “it does not mean that they are sinning, as each couple decides for themselves what they do or don’t do behind closed doors.”

If they do not display public disdain for the Torah, he said, they can act as leaders of congregational prayers.

For some, it is less about rabbinic legitimacy but writing a new script — carving their own path within Orthodoxy and believing that the tradition, in time, will follow.

As one member of Bat Kol, which supports lesbian women, said. “My love is not a problem. God loves me as I am.”

‘Queer Judaism - LGBT Activism and the Remaking of Jewish Orthodoxy in Israel’ by Orit Avishai (New York University), £25.99 is out now