Recent laws outlawing forced religious conversions in two Indian states are creating growing controversy.
The Pope has recently condemned the laws in the southern state of Tamil Nadu and Gujarat in the west of the country.
The country's Christian and Muslim minorities, which feel the laws are directed against them, say they undermine India's secular status and its constitution, which guarantees the freedom both to practice and to propagate one's faith.
Low caste Hindus show their bandages after they say upper caste Hindus attacked them
The laws, passed in Gujarat in April and in Tamil Nadu last October, forbid any religious conversions carried out through what they term "force, fraud or allurement", including the granting of material benefits.
They have proved highly popular with supporters of the Hindu revivalist ideology which now permeates India's central government.
Cho Ramaswamy, a colourful playwright-journalist close to Tamil Nadu's leadership, feels the legislation is reasonable.
"There have been complaints in various pockets of India that Christian sects are offering people education and financial assistance, but saying they must become Christian if they're to benefit," he says. "That is inducement."
But church and mosque leaders fear the broad new definitions will endanger their work, for instance in education or helping the poor.
These higher caste Hindus do not want the village deity paraded in dalit areas
Bishop Ezra Sargunam's Evangelical Church of India is a fast-growing independent church dedicated to spreading the Christian gospel.
He says the new law is already being abused.
"We have evangelists who've been stopped by the police - who say, hey, no proselytising here! You know there's a law against it?
"That's what we are bothered about," he says.
He is echoed by Abdul Jalil of a Tamil Muslim party, the TMMK.
People used to come forward voluntarily to accept Islam, says this mild-mannered scientist.
"Now people are coming out less," he laments. "They're going to neighbouring states like Kerala or Pondicherry because they don't want to convert here."
But there is one good reason people do still want to convert - Hinduism's rigid social hierarchy, the caste system.
At the very bottom are dalits, once known as "untouchables".
There's a sense of foreboding and doom
All-India Christian Council
For them, a new religion can mean a more equal existence.
In the little village of Koothirambakkam, I met some of these dalits who are being driven away from Hinduism by sheer caste hatred.
The higher-caste Hindus will not let the village deity be paraded through the dalit area, claiming the people are "unclean".
And in March, when dalits took up fishing rights in a pond, they were attacked.
A dozen villagers showed me their injuries.
One woman, over 70, was beaten until her hand was broken.
Another was cut on her arm, beaten and had abuse hurled at her.
Now these dalits have had enough and say they will convert to Islam.
That includes even Karunanidhi, 35, who has always devoutly adored one Hindu goddess.
"So many of us have suffered from these atrocities - now I'm angry with this goddess for not saving us," he says.
"So I'm leaving this religion for the sake of my people."
India's political leaders see this type of development and fear the majority religion - 80% of Indians are Hindu - is being eroded.
Bishop Sargunam says Christians working with him are stopped by the police
RBVS Manian of the right-wing Hindu movement, the VHP that is allied to the governing BJP, wants the new laws extended to ban all conversions, throughout India.
"The evangelists come and tell our people that our gods are all devils," he complains.
"We want to preserve the Hindu cultural identity of this nation, so the Hindu population should always be predominant."
Mr Manian says there can be "a few people" of minority faiths, but only "within a particular limit. We have to control it."
Such words frighten the religious minorities in Gujarat, where more than a thousand people died in sectarian riots last year.
Gujarat's new anti-conversion law has been accompanied by house-to-house police questioning of Christian nuns and priests, asking how many people they have converted.
The Gujarat law is now being challenged in court by the All-India Christian Council.
Conversions in Tamil Nadu went ahead despite a ban
"There's a sense of foreboding and doom," the council's secretary-general, John Dayal, warns.
He believes the central government in Delhi is also becoming "intolerant of the minorities".
"That's what makes it frightening."
Figures in the central government deny this.
They want more laws like this because, they insist, there are forcible conversions going on which insult Hinduism and create social disharmony.
But India's religious minorities fear the legislation is a sign that India's secularism is fading fast.