A Jewish man places a note at the Western Wall, the holiest site where Jews can pray, ahead of the Jewish New Year in Jerusalem's old city. (Sebastian Scheiner/AP)

Patricia Marks Greenfield is a psychology professor at the University of California at Los Angeles.

An American colleague and I traveled to Israel at the end of June to continue research with an Israeli team composed of Jewish and Muslim researchers from Ben Gurion University in Beersheba. Our team studies how rapid social change has shifted values among Arabs in northern Israel, Bedouin Arabs in the Negev and Ethiopians Jews in southern Israel — Israeli citizens all. In the course of this work, we have been warmly welcomed into the homes of our Arab partners in northern Israel. We also saw the home of a newlywed Bedouin couple that had been destroyed by Israeli bulldozers because some Bedouin ancestral lands are not recognized by the Israeli government, and we learned about racial discrimination against Ethiopian Jews.

Given these experiences, it seems more important than ever to state two things clearly and forcefully: Israel is a full-fledged multiethnic, multireligious society, and it must provide equal legal and day-to-day treatment to all its citizens, no matter their ethnic or religious background. Unfortunately, this is not the case for those who are Arab or Ethio­pian or whose religion is Muslim or Christian.

In this respect, Israel is out of step with much of the world. Over time, nations have become more ethnically and religiously diverse; populations have become more urban and educated; and economies have become more commercial. In response to these social and economic changes, many nations have left behind the notion of a favored state religion.

It is time for Israel to do the same. It must be a fully secular state.

What was necessary for Israel after the Holocaust is no longer necessary and has even become counterproductive. As long as being Jewish holds such a preeminent place in Israel, then Muslim and Christian Arabs will always be second-class citizens, vulnerable to discrimination in housing, employment, education and other areas. Nor can Ethiopian citizens be truly equal so long as their Jewishness and religious heritage are called into question by powerful religious authorities.

While we were doing our work in July, we were close to the fighting in Gaza. Our research activities were disrupted by rocket fire. We could hear, and feel, rockets falling to the ground or being intercepted by the Iron Dome antimissile system. It was nerve-wracking to live this way, and I have a new understanding and respect for what Israelis go through in wartime.

But I also understood for the first time what Isaiah Berlin said of Israel: “Too much history, too little geography.” The cut-off nature of the Gaza Strip means that, geographically, Gaza is, in reality, a part of Israel, while continuing Israeli settlement on the West Bank means that Israel has made itself part of Palestine. Gaza and the West Bank may be separated from each other, but they are not separated from Israel. Given this reality, Gaza and the West Bank must inevitably become part of Israel; there can be no two-state solution. And Israel must leave behind its official Jewish identity to acknowledge its multiethnic, multireligious character by providing equal treatment for all.

The Muslim Israelis with whom we worked as researchers, and the Arab communities we studied in northern Israel, are committed to Israel. Their commitment is based on their long history on the same soil, reinforced by the economic and educational opportunities that Israel provides. But this commitment could become even stronger if Muslim and Christian Israelis were treated the same as Jewish Israelis. As for Ethio­pian Jews, their joy and relief at reaching Israel would be renewed, were their unique history to be respected.

Many Jewish Israelis subscribe to the unfortunate demographic myth that high birth rates among Arabs and Ethiopians mean that they will soon outnumber Jews of other national and racial origins. But education and economic opportunity unfailingly drive birth rates down. If Israeli minorities were provided with the same educational and employment opportunities as other Israelis, their birth rates would decline to the same levels and their proportion in the population would stop increasing. Between the 1960s and 2004, as Arabs in Israel became more prosperous, educated and technologically connected, their birth rate fell by more than half, according to the Israel Central Bureau of Statistics. Indeed, the bureau’s figures for 2013 revealed that the Jewish birth rate is rising as the Muslim birth rate continues to decline. This is one important reason why Israel will continue to have a culture rooted in Judaism.

If Gaza and the West Bank were truly part of Israel, and Israel were truly a multiethnic, secular society, there would be progress toward peace. The “right of return” championed by Arabs would have new meaning: It would no longer mean the transfer of Israeli land. Instead it would mean the opportunity to live in Israel as fully equal citizens, with all of the privileges from and obligations to the Israeli nation. Internal equality and external peace are two sides of the same coin.