SEOUL (Reuters) - Many South Koreans concerned about the country's increasing religious polarisation are haunted by a single image - their president on his knees.
While attending a national prayer breakfast in March, Lee knelt to pray at the urging of Christian leaders.
Footage of the event shocked many in this pluralist country, where about half the population professes no particular faith and the remainder is split between Buddhists, Christians and homegrown creeds.
The main Buddhist Jogye Order called the scene "unforgiveable," and even right-leaning media outlets generally supportive of the conservative leader expressed reservations.
The Joongang Ilbo daily in an editorial urged Lee, a devout Protestant and an elder at Seoul's Somang Church, to keep his beliefs private and avoid provoking public ire.
"(The prayer breakfast) convinced people how dangerous the current situation really is," said Park Gwang-seo, head of the Korea Institute for Religious Freedom, a civic group that works to promote the separation of religion and state.
"We're at a peak as far as the relationship between politics and religion is concerned."
South Korea's constitution stipulates that there is no official religion and bars the country's leaders from elevating one faith above others, but analysts say Lee's outspoken religious beliefs and strong links with the Christian community have opened the administration to charges of bias.
"We have for the first time very high-level conflicts going on, particularly between the Christian community and the Buddhist community," said Hahm Sung Deuk, a professor of political economy at Korea University. "And most of these conflicts can be attributed to President Lee."
Buddhists, secularists and even some Christians have bristled at cases that they believe point to a rising Christian influence in the operations of government.
These include its failure to pass legislation supporting Islamic bond, or sukuk, issuances, which was strongly opposed by Christian groups, and a reduction in funding for a program that lodges tourists at Buddhist temples.
Many also believe Lee filled key government positions based on recommendations and advice from the Christian community, Hahm says.
Christian groups say they enjoy good relations with the administration, but deny having any direct influence.
"Some people might say the church and state are too friendly, but it's not favourable for the church to participate in politics," said Kim Woon-tei, executive secretary of the Christian Council of Korea (CCK), which claims to represent around 8 million people under 69 protestant denominations.
"We only give our opinions to the state, to show how Christians view politics and the political process."
The Council's opposition to sukuk laws was not based on religion but because the proposals "(did not serve) the well-being of the economy and Korean people," Kim said.
A sense they are being left behind has mobilised Buddhists, who are increasingly flexing their political muscle, observers say.
"Buddhists think Christians are getting too much support (from the government)... so are organising more clearly to express themselves through political action and as a political movement," said Yoon Yee-heum, an honorary professor of religious studies and Seoul National University.
In late 2010, the Jogye Order cut off relations with the ruling Grand National Party (GNP) over the temple funding row, barring its officials from attending official temple events even throughout the campaign period for April by-elections, when candidates frequently do the rounds of prominent temples and churches.
The dispute appeared to reach a resolution on June 7, when the head of the order announced that despite the government's "religious favouritism", it would normalise ties with the ruling party and endeavour to resolve any issues through "communication and an open approach."
The timing of the peace with the Jogye Order is fortuitous for the GNP as political parties move to galvanise support ahead of the presidential election next year. In an increasingly charged environment some fear religion could play a bigger role in the results.
Kim of the CCK says while the organisation does not officially endorse specific candidates or parties, its membership is largely conservative and some church leaders "may say they are favourable to certain politicians and candidates."
Park of the Korea Institute for Religious Freedom said: "Most priests speak about politics and many people are affected by their opinions."
Others believe the impact of religious groups on the vote will be minimal and that elections could even ease the tensions that have characterised the Lee administration.
"Voters don't care much about candidates' religion itself, but how it relates to their governing," said Korea University's Hahm.
Hahm said the figures generally tipped as presidential candidates, including apparent front-runner Park Geun-hye, are careful to be circumspect about their religious views. Park aides say she professes no specific faith.
"Because of the Lee experience, many candidates will be very careful about the religious issue or selecting people from a particular religious group," he said. "They know the majority of Koreans support the principle of separating religion and politics and will try to get as much support as possible across religious communities."
Yoon warns candidates who ignore the conflicts that have arisen in recent years and turn to religion to win support may further imperil the harmony that has so far characterised relations among Korea's different faiths.
"If politicians do not look at this change, no one knows where the situation will go," he said. "Politicians see religion as a voting matter, so they're ignoring it ... (it is) clearly rising as a social problem."
Additional reporting by Seongbin Kang, Editing by Jonathan Thatcher and Sanjeev Miglani