As Rabbi Dovid Ben Meir leads visitors through the ruins of this ancient city, believed to have served as the Jewish capital more than 3,000 years ago, his love of history is clear. But it wasn't his love of the past so much as his desire to shape the future that led him here. When he was a teenager in Chicago, a class on modern European history got him thinking: In every revolution, there are people for, against, and indifferent. "I wanted to say to myself that I would be for revolution, for progress. But I was born 200 years too late."

Then he had a second thought.

"I realized there was something immense going on in the world – the restoration of the state of Israel, the redemption of the people of the Jewish nation," recalls the rabbi. His parents were both Holocaust survivors, barely – his father was pulled off a mound of bodies when someone saw him move. "I wanted to take part in building a better future, the building of the Jewish nation in the land of Israel."

Today, he is a father of nine and lives with his wife in aWest Bank settlement near Shilo.

It's communities like his that the United Nations rejected on Nov. 29, when an overwhelming majority of member nations affirmed the right of Palestinians to establish a state here.

Since Israel captured East Jerusalem and the West Bank in a 1967 war with its Arab neighbors, the Jewish population in these areas has grown from virtually zero to at least 550,000, leaving Palestinians with shrinking patches for a homeland.

Many in the international community view settlements politically, as a maneuver to maximize the Israeli advantage in negotiations with Palestinians – or to scuttle those talks entirely. For peace negotiations to resume after a four-year deadlock, Palestinians have called on Israel to freeze settlement construction for six months. Ultimately, they and many others want the settlers to leave the past behind and go back across the pre-1967 border.

But for religious Zionists like Mr. Ben Meir, being here is not just about the past but about fulfilling a divine commandment to resettle the land that God promised to Abraham, Isaac, and Jacob. And they believe that doing so is part of a process that is fulfilling biblical prophecy and ushering in a messianic age. Those beliefs represent a major challenge to the prospects for a two-state solution, as the idea of a covenant made with God is effectively nonnegotiable, whereas political objectives or positions can often be adjusted in return for other benefits.

Religious Zionists have never made up a majority of settlers. But shortly after Israel more than doubled its territory in 1967, they became the most visible and energized proponents of settlement, especially in areas deep in the West Bank. They steadily gained leverage over divided governments, and today carry outsized influence on government decisionmaking, serving as a kind of "internal deterrence" to any Israeli leader weighing an exchange of land for peace, saysGershom Gorenberg, a historian of Israeli settlement.

These religious Zionists describe the redemptive era they espouse as already well under way, and say it includes the coming of the Messiah, who is widely expected to be a human leader; the rebuilding of the temple in Jerusalem; the uplifting of all peoples; and the establishment of lasting global peace.

Evolution of religious Zionism"Everything that happens, there's a divine reason and a divine hand behind it," says David Wilder, spokesman for the Israeli settlers of Hebron. "We believe that our being back here is a stage in the redemption of the Jewish people, which will culminate in some point in time with mashiach," the anointed one, or Messiah.

When Zionism began gathering momentum as a secular European movement to establish a home for the Jewish people, many religious Jews looked askance at it. Many denounced it as a heretical plan to try to hasten God's redemptive process.

Enter Rabbi Abraham Isaac Kook, a renowned Torah scholar originally from the Russian Empire, who incorporated teachings from the mystical branch of Jewish thought known as kabbalah. He argued that Zionists were an unwitting part of the divine plan to bring the exiled Jewish people back to Israel, or Zion, and that it was incumbent upon religious Jews to take part – and eventually persuade their secular brethren of the divine mission they shared.

In 1924, while Palestine was still under British rule, Mr. Kook founded the Mercaz HaRav yeshiva in Jerusalem, which became a spiritual and intellectual headquarters of religious Zionism.

He and his son cultivated generations of religious Zionists, including Ben Meir, who arrived from Chicago as a teenager.

On a recent evening, the yeshiva was pulsating with Hanukkah music as the latest crop of students celebrated.

"That's one of my students on the guitar," says Rabbi Yehoshua Magnes with a twinkle in his eye, listening to the concert from his apartment across the street. Surrounded by hundreds of books, he marvels at the depth of Jewish thought and philosophy cultivated during nearly 2,000 years in exile.

He sees the ingathering of the exiles in Israel as part of a messianic process, but says he doesn't know what shape the Messiah will take or when he will come. As for where, he cites a 12th-century rabbi and philosopher from Spain, Rabbi Judah Halevi, who wrote that the land of Israel is the only place where a person can be a prophet – which is to say, someone who has a direct connection with God.

Mr. Magnes refers to a page in the Talmud that says that the Messiah will come on clouds – or on a mule. "If we do it the easy way, then he'll come on clouds.... But if we do it the hard way, we're talking about a lot of suffering," he says.

Given the Holocaust and sufferings in the land of Israel over the past 100 years, he says, "then I can't say he's coming on clouds.... But it's coming."