On a visit to Jerusalem, Robertson spoke repeatedly in favour of Israel and lambasted Arab countries, warning that the establishment of a Palestinian state would threaten Israel's survival and interfere with "God's plan".
Israel captured east Jerusalem in the 1967 Middle East war and later annexed the section of the city as part of its capital. Palestinians want east Jerusalem for the capital of a future state. The city is revered by Muslims, Jews and Christians.
Most nations, including the United States, never recognised Israel's annexation of east Jerusalem and keep their embassies in Tel Aviv.
According to Robertson, evangelical Christians - estimated at tens of millions of Americans - overwhelmingly support Bush for his pro-Israel policies,
"But if he touches Jerusalem and he really gets serious about taking east Jerusalem and making it the capital of a Palestinian state, he'll lose virtually all evangelical support," Robertson said on Monday. "I think this is the key issue."
Bush had promised in his election campaign in 2000 to move the US embassy to Jerusalem as a sign of US backing for Israel's hold on the city.
But he later thwarted congressional action to move the embassy, reflecting official US policy that the fate of the city should be negotiated by Israel and the Palestinians.
Robertson said Israel should not have to give up land for a Palestinian state but Jordan, Saudi Arabia and Egypt should take in the 3.5 million Palestinians living in the West Bank and Gaza Strip.
Robertson accused Islam of wanting to destroy Israel.
Bush promised in 2000 to move
the US embassy to Jerusalem
"I see the rise of Islam to destroy Israel and take the land from the Jews and give East Jerusalem to the Palestinian Authority. I see that a Satan's plan to prevent the return of Jesus Christ, the Lord," said the broadcaster.
The founder of the Christian Broadcasting Network said he favoured Israel over the Palestinians, saying: "It isn't a question of politics, it's just a question of God's plan."
He added that Jews and Christians have a common heritage and a different God from the Muslims.
The Virginia-based television evangelist is visiting Israel as a guest of the International Christian Embassy Jerusalem.
More than 4000 evangelical Christian pilgrims are touring Israel during Sukkot, the Feast of the Tabernacles, a Jewish holiday some Christians also celebrate.
Some evangelical Christians in the US follow the doctrine of dispensationalism, which, among other things, stipulates that the creation of Israel in Palestine in 1948 was a fulfilment of Biblical prophecy and presages the second coming of Jesus Christ.
Some evangelist leaders have supported Israel's atrocities against the Palestinians, such as the 1982 Sabra and Shatila refugee camp slaughter as well as the Jenin refugee camp massacre in 2002 on the grounds that such events ushered in the second coming of Jesus.
"But if he [Bush] touches Jerusalem and he really gets serious about taking east Jerusalem and making it the capital of a Palestinian state, he'll lose virtually all evangelical support"
American television evangelist
There are also evangelical doctrines teaching that a universal apocalyptic war between good and evil, called Armageddon, will take place in Palestine in which most Jews will be annihilated except some 40,000 who would accept Jesus and become Christians.
The evangelicals are considered some of Israel's strongest supporters in the West, especially in the US where they hold a swaying influence on the Republican party and could help to determine the outcome of the current presidential election campaign.