What is a “religion” that needs to be accommodated?
Title VII defines the term “religion” to “include all aspects of religious observance and practice, as well as belief.” According to Equal Employment Opportunity Commission (EEOC) guidelines, a religious practice includes “moral or ethical beliefs as to what is right and wrong which are sincerely held with the strength of traditional religious views.” The religion does not need to be widely practiced, formally organized, or include traditional religious elements such as a belief in a superior being or the afterlife.
Cost is not the only consideration in deciding whether an accommodation creates an undue hardship.
Courts will also consider the burden on the business generally.
(For example, if a company allowed employees to engage in pitched arguments over politics, it would be difficult for that company to justify a complete crackdown on discussions of religion.) It's not entirely clear what these rules mean in practice.