Religious employees feel under pressure to keep their beliefs and faith symbols hidden at work, a watchdog has found.
The Equality and Human Rights Commission found those who were openly Christian complained of being mocked as bigots, sometimes because of their stance on same-sex relationships.
Jewish and Muslim workers reported finding it hard to get time off work for religious reasons.
A total of 2,483 organisations and individuals took part in the research.
The watchdog found widespread confusion and misunderstanding about the laws protecting freedom of religion or belief.
The research will inform a report on the adequacy of those laws and it is also looking to issue guidelines for employers and those who provide services to the public.
The highest number of responses came from Christians, some of whom say they fear their religion is losing its place in the workplace and in society more generally.
Some Christian businesses reported being "in turmoil" over whether actions might breach the Equality Act, aimed at preventing discrimination in the workplace.
Its research also revealed that atheists and humanists who responded to the survey said they had experienced unwanted conversion attempts and felt excluded from company events held in religious buildings.
Both Christian and humanist parents said their children had been ridiculed at school.
Examples cited by people who responded to the survey include a Catholic who was unable to wear a crucifix or rosary while others had nose rings and piercings and a law firm manager who faced objections to organising a Christmas party as it promoted religion.
Mark Hammond, CEO of the Equality and Human Rights Commission, said the research showed a "complex picture" of different opinions and experiences.
"What came out strongly was the widespread confusion about the law, leading to some resentment and tensions between groups and anxiety for employers who fear falling foul of what they see as complicated equality and human rights legislation," he said.
"How the law deals with religion and other beliefs in work, in providing services and in public debate has become a matter of considerable controversy."
However, he said they also found employees who had had positive experiences of "diverse and inclusive workplaces".