How am I protected from religious discrimination?

If you are a citizen of the United States, the First Amendment to the Constitution says that everyone has the right to worship or not to worship as they please without fear or interference from the government. Constitutional guarantees only go so far. As to discrimination, there are two types: overt and covert. Covert is the discrimination that is institutionalized and while a person may be aware of it, the discrimination is subtle and nearly undetectable. Overt is open and public, whereby a person encounters hostile and discriminatory actions specifically due to their religious beliefs.
In the workplace, a person is protected from all types of discrimination, including religious, by federal and some state laws. Prohibited in the workplace by law is the intentional discrimination in benefits, pay, hiring, termination, job assignments, promotions, layoff, training, or other benefits accrued by being an employee of a company. Although you may be protected by the law, employees have to follow a process and procedure which begins with filing a complaint with the employer. If this does not solve the problem, an employee may file a complaint with state and federal government labor organizations.
Religious discrimination should be treated no different from other forms. However, because of the nature of religion and the number of different religious beliefs, religious discrimination remains hard to end.
https://www.aclu.org/other/your-right-religious-freedom

https://www.citizensadvice.org.uk/law-and-courts/discrimination/discrimination-because-of-race-religion-or-belief/discrimination-because-of-religion-or-belief/

https://www.eeoc.gov/laws/types/religion.cfm