With tensions already high in Gujarat from last year's bloody Hindu-Muslim rioting, the state's Hindu nationalist government is worrying the small Christian minority by sending police around with questions about their religious beliefs and practices.
Christians fear the Bharatiya Janata Party plans to interfere with their right under India's constitution to propagate their faith.
Since its landslide victory in December's legislative elections, the BJP has proposed a law to ban religious conversions by coercion or inducement, as two other Indian states have done since the party won control of the national government in 1998.
Hindu hard-liners contend such laws are needed to combat what they say is a Western conspiracy to undermine India's majority Hindu faith. They accuse Christian missionaries of tempting poor tribal people and low-caste Hindus to convert by offering jobs and money.
Christians, who make up 2.4 percent of India's 1.02 billion people, say no one can force or pay someone to make a spiritual decision.
Two weeks ago, four-man police teams began visiting Christians at churches, homes and businesses across this western state.
Carrying small red notebooks and a one-page questionnaire, the officers ask: "Were you a Hindu earlier? When and why did you convert? Are you getting any money every month from Christians? Do you read the Bible? Why did you convert? Do you want to be reconverted to Hinduism?"
"Some of the questions annoyed me but I could not say so. Who wants to argue with the police?" said Pranav Sharon, who added that the officers also asked if his grocery shop is financed by Christian groups.
Sharon worries policemen will come back to embarrass him.
"I felt bad, though I have not committed a crime. My customers ask why the police were here for half an hour," said Sharon, 42, who converted from Hinduism to Christianity, along with his wife and three children, 23 years ago.
Sharon was among more than 12,000 Christians questioned in the first two weeks in Gujarat, where more than 1,000 people died in last year's religious riots. The governing party has been accused of letting police help Hindu mobs attack Muslims.
A group of Christian organizations has petitioned the state High Court seeking to halt the survey on the grounds it "unlawfully targets" Christians. The All India Christian Council said Christians are being "harassed and victimized in the name of collecting census information."
The High Court gave police until April 10 to explain why the survey is not illegal. Another petition, filed with India's Supreme Court, will be heard April 6.
The state government says the survey is being conducted to answer a question by a lawmaker in India's federal Parliament about the financing of Christian and non-governmental organizations. "There is nothing for Christians to fear," said Gujarat's home minister, Amit Shah.
Christian organizations don't agree.
In November, the southern state of Tamil Nadu imposed a three-year jail term for anyone found guilty of inducing or coercing someone to convert religions. The eastern state of Orissa also requires people to get permission from the local government to change their faith.
Christians have traditionally run schools and hospitals across India and there are fears among them that providing medical aid or education could be construed as an "inducement" to convert. Many Hindus attend Christian schools.
In 1999 there was a surge of violence against Christians in India. More than 50 prayer halls and churches were burned in Gujarat, Orissa and Bihar, and an Australian missionary and his two young sons were burned to death in their jeep by a Hindu mob.