LANCASTER, Pa. (AP) — A former Pennsylvania mail carrier says the U.S. Postal Service violated his rights by requiring him to work Sundays.

Gerald Groff, who says he is an evangelical Christian, filed a lawsuit Friday against the federal agency, claiming he was let go from his position after refusing to work on Sundays for religious reasons.

The federal lawsuit claims Groff worked “flexibly” to accommodate his convictions by offering to pick up holiday, evening and Saturday hours that others did not want to work.

Groff, who worked for the Postal Service for seven years, said the agency began enforcing a no-exceptions Sunday policy on him and “needlessly disciplined him,” according to a statement released by his defense Monday. The disciplinary methods included suspensions as long as two weeks.

The statement said he was eventually let go from his position.

“In a free and respectful society, government should recognize those differences among us that make us great, rather than punishing those differences, particularly when those differences result from our sincerely held religious beliefs,” said David Crossett, one of the attorneys representing Groff.

The Postal Service does not generally comment on pending litigation, a spokesperson told Lancaster Online on Monday.

The lawsuit is seeking reinstatement of Groff’s position with accommodation, back pay and unspecified compensation for emotional distress. The complaint also requests for the agency to create policies that provide equal employment opportunities for religious observance of Sabbath on Sundays.

The Postal Service is an independent government agency that does not use taxpayer money for its operations.