Supreme Court showdown over Sabbath could change workplaces across US

LANCASTER COUNTY, Pa. -- Rain or shine. Sleet or snow. Just not on the Sabbath.

Former U.S. Postal Service letter carrier Gerald Groff spent every day for seven years delivering the mail in a rural corner of southeast Pennsylvania -- except for Sundays when he would attend worship services and rest.

But in 2019, the former Mennonite missionary and son of a truck driver said his boss forced him to choose between practicing his faith or a paycheck distributing packages, and he resigned.

"I want to own what I believe and live that out for God," Groff told ABC News in an interview in his hometown of Lancaster County.

Next week, Groff will ask the U.S. Supreme Court to require employers to be more accommodating of religiously observant workers, including a right to skip shifts on the Sabbath and still keep their jobs.

The case has the potential to transform workplaces -- and the employer-employee relationship -- across America, experts say.

"I didn't really think I should have to quit. I really expected the post office to find a way to accommodate me and make it work for both them and myself," Groff said.

Federal law requires employers to accommodate the religious beliefs of workers unless it would impose an "undue hardship" on business -- a standard the Supreme Court interpreted 46 years ago to mean anything more than a "de minimis cost."

The USPS says Groff's refusal to work Sundays imposed a significant cost on operations, alleging the absences "created a tense atmosphere" and bred "resentment toward management" and that the need to find substitutes was "time consuming," according to court documents.

Two lower federal courts agreed.

"An employer is not required to accommodate at all costs," wrote a panel of judges from the U.S. Third Circuit Court of Appeals. "Exempting Groff from working on Sundays caused more than a de minimis cost on USPS because it actually imposed on his coworkers, disrupted the workplace and workflow, and diminished employee morale."

The Postal Service does not deliver mail on Sundays, but beginning in 2015 carriers nationwide were contracted to help deliver packages for the online retail giant Amazon. The USPS says the arrangement has been a major source of revenue in the face of declining traditional mail.

"They began to ask people in my position to deliver on Sundays or holidays, and I told them, 'I'm not going to be able to work on the Lord's day at all,'" Groff said. "The Bible says that we're supposed to keep the Lord's day as unique and holy, a day that's set apart to worship and honor God."

Title VII of the Civil Rights Act of 1964 makes it unlawful "to discriminate against any individual with respect to his compensation, terms, conditions, or privileges of employment, because of such individual's ... religion," unless an employer can show that "reasonably accommodating" the employee would create "undue hardship" on the business.

At first, the local postmaster accommodated Groff, tapping substitute carriers to take Sunday shifts at his rural post office. He says he picked up an extra route in exchange.

But one year later, Groff says his boss told him things had changed.

"She said, I'm not going to put up with your [expletive] this year," he said. "And she said, basically, you're going to have to find another job or you're going to work Sundays this time."

Unwilling to compromise his faith, Groff transferred to a smaller post office nearby -- one that had just four carriers and still did not work on Sundays. But as demand for Amazon deliveries continued to grow, he eventually could not avoid Sunday assignments.

Groff chose to skip 24 Sunday shifts over two years, according to court documents. He said splitting the day -- attending worship services while also picking up a shift -- was not an option.

"I told my supervisor, 'It's the Lord's day. It's not the Lord's morning,'" Groff said.

After being repeatedly disciplined for not showing up, Groff resigned in 2019 and sued USPS for religious discrimination.

The company declined to comment to ABC News on the case beyond what it told the Supreme Court in its legal brief, which rejects the claim of discrimination and argues that accommodating Groff was not legally required.

ABC News spoke with several postal service union representatives and veteran former carriers unconnected to the case, all of whom generally validated the company's insistence that Groff's request to skip Sundays created an "undue hardship."

"The only replacements are who we had in the office, and we were short-staffed already. So we had to double up and work long hours," Scott Arnold, a former USPS carrier and union leader for 41 years in Virginia, said of absences among colleagues.

Workforce shortages at USPS have been persistent and growing, according to a bipartisan group of U.S. senators who recently wrote to Postmaster General Louis DeJoy seeking steps to shore up service.

"Employees have shared with us that they are working long hours, with little or no days off, to deliver mail in a timely fashion," the group wrote in a January letter. "Further, they have shared that workforce morale is low, leading to current staff pursuing other opportunities and making prospective staff skeptical of joining the USPS."

Rob Receveur, who retired from the USPS last year, said a colleague who might have sought religious exemption from Sunday shifts would likely not have been viewed kindly by peers.

"It would be a negative reaction. Maybe it's legitimate, and you'd say, 'OK, that's an exception,' but a lot of people don't react that way," Receveur said.

"The hardship would be created if [the post office] didn't have proper staffing, and they don't have proper staffing," added Arnold. "The other part of the problem is equity: Do I have to go join this religion so I can get something?"

Groff says the bar for an employer legally refusing to accommodate sincere religious practice needs to be higher. But critics warn that could create a sweeping impact on non-observant Americans.

"This case opens the floodgates to every employee in the workforce being forced to carry the burden of someone else's religious practices," said Rachel Laser, president and CEO of Americans United for Separation of Church and State.

Laser argued that a Supreme Court ruling in favor of Groff could empower pharmacists to not fill birth control prescriptions, city clerks to object to issuing same-sex marriage licenses and employers to treat men and women differently -- invoking religious belief or practice as justification.

"This would lead to special favor for some of us and asking the rest of us to carry the harm of what someone else is imposing on us," Laser said.

Groff's attorneys insist those concerns are overblown.

"Why in the world do you want to get rid of the guy who's going to deliver on Thanksgiving Day and deliver two shifts on a Saturday and go into the night all the rest of the days [of the] week over a few Sundays that we can always schedule around?" asked Hiram Sasser, executive general counsel for First Liberty Institute.

For his part, Groff said he doesn't want to be a burden on anyone else but also wants to be able to practice his faith and keep his job.

"I was willing to work every holiday. I was equally as inconvenienced by the Amazon contract as [other employees] were. It was not something I signed up for. It was imposed upon us when they, when the post office, signed that contract," he said.

"I can't fix what happened to me, but if we could stop that from happening to somebody else," he said, "I would consider that a win,"

The Supreme Court will hear oral arguments in the case on Tuesday and issue a decision before the end of June.