The Supreme Court ordered the 3rd Circuit to reconsider the matter.
The Supreme Court, with its 6-3 conservative majority, has a track record of expanding religious rights, often siding with Christian plaintiffs.
Groff's attorneys had asked the Supreme Court to overturn the Hardison precedent and require companies to show a "significant difficulty or expense" before denying an accommodation.
The Postal Service in 2013, in a bid to remain profitable, contracted with Amazon.com to deliver packages, including on Sundays.
His absences caused tension among other carriers who had to cover his shifts, the Postal Service said.
Persons:
Gerald Groff, Hardison, Groff, Andrew Chung, Will Dunham
Organizations:
U.S, Supreme, Postal Service, Circuit, Appeals, Civil, VII, Airlines, Amazon.com, Thomson
Locations:
Pennsylvania, Philadelphia, Pennsylvania's Lancaster, United States, Colorado, Washington