The U.S. Supreme Court is scheduled to consider a case April 18 that could have broad implications for employees seeking religious accommodations from their employers.

The high court is scheduled to hear oral arguments in Groff v. DeJoy, a case concerning Gerald Groff, an evangelical Christian and former U.S. Postal Service worker, who was denied an accommodation to observe his Sunday Sabbath by not taking Sunday shifts.

Federal law prohibits employers from firing employees for who request religious accommodations unless the employer can show that the worker's religious practice cannot be "reasonably" accommodated without "undue hardship." The Supreme Court issued a 1977 decision in Trans World Airlines v. Hardison finding that the "undue hardship" standard is met even at a minimal cost.

Groff alleged in federal court that USPS failed to provide him with reasonable accommodations for his religious practices. The U.S. Court of Appeals for the 3rd Circuit ruled in favor of USPS, arguing the post office would face "undue hardship" by accommodating Groff's request to excuse him from Sunday shifts.

But the U.S. Supreme Court agreed earlier this year to take up the case.

Randy Wenger, chief counsel of the Independence Law Center, a group representing Groff, told OSV News that Groff "has a very strong conviction about Sunday being the Lord's Day," which caused him to seek employment at a place that was closed on Sundays.

"In a pluralistic society, it's really important to be able to find those ways to accommodate so that we can all work together effectively," he said.

Wenger said when the post office reached an agreement to deliver some Amazon packages on Sundays, Groff sought accommodations to not work those shifts. He was initially accommodated, then disciplined for his refusal to work Sundays. He later resigned to avoid violating his convictions.

"If we're committed to protecting religious conscience, we need to make sure employees don't lose their jobs for following their faith," Wegner said. "It's kind of like freedom of speech, you might not like what somebody has to say, but their ability to say what they say helps you say what you want to say."

In a court filing, attorneys for USPS argued that "simply skipping (Groff) in the rotation for Sunday work would have violated both a collectively bargained (memorandum of understanding) and a specific settlement." USPS attorneys added the accommodation would have created "morale problems" among his colleagues.

Mark Rienzi, president and CEO of Becket, a religious liberty law firm that has filed a friend-of-the-court brief in the case, told OSV News the Supreme Court's previous ruling on the minimum standard in Hardison is not in keeping with the intention of the federal law.

"So essentially, if it costs the employer anything at all to accommodate, the employer doesn't have to accommodate," he said of the previous ruling. "The whole point of the law was to actually protect the employees unless it was some real hardship on the employer. And instead of requiring hardship, what the court said was actually it doesn't really have to be a hardship."

Rienzi said he is optimistic the court will fix its previous interpretation.

"I strongly suspect they're going to fix it and acknowledge it made no sense," he said.