By Richard Allen Greene, CNN

(CNN) - Half the world's evangelical Protestant leaders are optimistic about the future, confident that evangelical Christians have an increasing influence in their countries and that things will be better for them in five years.

The other half are pessimists, convinced they're losing influence on the life of their countries and mostly not persuaded that things will be better for Christianity where they live in the future.

Those are among the findings of a groundbreaking survey of more than 2,000 evangelical leaders from around the world, which the Pew Forum on Religion & Public Life released Wednesday

The split on optimism is between north and south, and the way it breaks down might surprise you.

It's evangelicals in the comparatively poor south who see a bright future ahead - Africans, Latin Americans and Middle Easterners.

Those from the developed world, where evangelical Christianity was born, are the pessimists. And Americans are among the most glum of all, with more than eight out of 10 evangelical Christian leaders there saying that the movement is losing influence in the United States today.

Among other results from the survey:

- Only 3% of evangelical Christian leaders believe in evolution as defined by scientists. About half believe God created the planet and life on it as it is now, while four out of 10 say there has been evolution, but it was guided by God.

- Nearly all believe abortion is usually or always morally wrong. A similar number say the same thing about homosexuality.

- They feel generally positive about Catholics, Orthodox Christians and Jews but have a low opinion of Buddhists, Hindus, Muslims and atheists, with atheists rating the lowest of all. (Evangelicals from Muslim-majority countries tend to have higher opinions of Muslims than those who live elsewhere, the Pew Forum found.)

- Half say the Bible should be read literally. Half say not everything in it should be taken literally.

- Half say it is necessary to believe in God to be a moral person. Half say it isn't.

Pew Forum Director Luis Lugo said the "optimism gap" between north and south struck him the most about the survey.

"There are huge differences between the global south, who see things getting better, compared to the global north, and particularly the U.S., where we get down to 31% who see things being better five years from now," he said.

But the respondents' perceptions may not reflect reality, said Michael Cromartie, an expert on evangelical Christians and a senior adviser to the Pew Forum not involved in the survey.

"In the United States, evangelicals feels like they're losing influence because the elite culture isn't sympathetic or sees them as intolerant - which I don't think it is the case, but it's how they're perceived," said Cromartie, who directs the Evangelicals in Civic Life program at the Ethics and Public Policy Center in Washington.

In the global south, on the other hand, "You could see yourself having influence because the numbers (of evangelical Christians) are growing so fast," he said.

"The numbers are exploding. That doesn't necessarily mean you have influence, but you feel like you have influence."

Both sides think the south - where a majority of evangelicals now live - should have more influence on the movement as a whole, the survey found.

"We were surprised to see a majority thought that the global south should be contributing more - and leaders from the global south were even more self-critical," Lugo said.

Leaders from the south tend to be more conservative than those from the north, a pattern that mimics that in the global Anglican Communion, for example. If the south gains influence over time, it could push the movement as a whole in an even more conservative direction.

But Lugo points out that the south is not a monolith.

"Latin America is much closer to North America and Europe than to the rest of the global south" in its attitudes, he said. "They tend to be less conservative on homosexuality even than European leaders, and less conservative on tithing and biblical literalism than the rest of the global south."

The Pew Forum surveyed 2,196 participants in the Third Lausanne Congress on World Evangelization held in Cape Town, South Africa, in October. The respondents were leaders sent by their home churches and mirror the geographical map of evangelical Christians around the globe, the Pew Forum said.

There are at least 260 million followers of the movement worldwide, the Pew Forum said.

The conference where it conducted the survey is a follow-up to one Billy Graham convened in 1974 in Switzerland.