“We think it’s crucial that the Muslim world realize that there are evangelical Christians in the U.S. in large numbers that want a fair solution,” Mr. Sider said.

In the last year and half, liberal and moderate evangelicals have initiated two other efforts that demonstrated fissures in the evangelical movement. Last year, they parted with the conservative flank by campaigning against climate change and global warming. This year, they denounced the use of torture in the fight against terrorism. Some of the participants in those campaigns also signed this letter.

The Rev. Joel C. Hunter, senior pastor of Northland Church in Longwood, Fla., said, “There is a part of the evangelical family which is what I call Christian Zionists, who are just so staunchly pro-Israel that Israel and their side can do no wrong, and it’s almost anti-Biblical to criticize Israel for anything. But there are many more evangelicals who are really open and seek justice for both parties.”

The loudest and best-organized voices in the evangelical movement have been sending a very different message: that the Palestinians have no legitimate claim to the land.

The Rev. John Hagee, who founded Christians United for Israel, was informed of the letter and read most of it. He responded: “Bible-believing evangelicals will scoff at that message.

“Christians United for Israel is opposed to America pressuring Israel to give up more land to anyone for any reason. What has the policy of appeasement ever produced for Israel that was beneficial?” Mr. Hagee said.

“God gave to Abraham, Isaac and Jacob a covenant in the Book of Genesis for the land of Israel that is eternal and unbreakable, and that covenant is still intact,” he said. “The Palestinian people have never owned the land of Israel, never existed as an autonomous society. There is no Palestinian language. There is no Palestinian currency. And to say that Palestinians have a right to that land historically is an historical fraud.”