Senior Australian Catholics have warned that marriage equality should not be a matter of “winner takes all” five months after unsuccessfully advocating a no vote in the postal survey which led to its legalisation.

Fourteen years after the Howard government defined marriage in the civil law as exclusively between a man and woman – a move supported by the Catholic church – Michael Casey from the Australian Catholic University (ACU) told a parliamentary inquiry into religious freedom that laws should help people with differing views on marriage “live and let live”.

At a hearing on Wednesday numerous witnesses from organised religions told the joint standing committee on foreign affairs, defence and trade inquiry that marriage equality has changed Australian culture and laid bare the fragility of protections for religious freedom.

Casey, who is the director of the PM Glynn Institute, a public policy institute within the ACU, said there are different views in society about “what a marriage is” and how far it extends.

The parliamentary inquiry is separate to the Ruddock review of religious freedoms which has opted for secret hearings and has heard complaints that religion is being forced from the public square as a consequence of the changed definition of marriage in the civil law.

In submissions to the Ruddock review, the Equality Campaign – which won the postal survey campaign – called for exemptions in discrimination law that allow religious institutions such as schools, hospitals and aged-care facilities to discriminate against staff and clients based on beliefs to be abolished.

Religious exemptions were a focus in the campaign because of a threat from the Catholic church to sack staff who engaged in same-sex marriage and because of the sacking of a gay teacher in Western Australia.

Submissions to the Ruddock review from Christian schools have sought to protect their right to hire and fire teachers based on adherence to religious practice while the Catholic church and Sydney Anglican church have called for a religious freedom act to positively protect religious exemptions to discrimination law.

Casey, who was not asked about the Catholic threat to sack their staff, said Australian society needed to discourage the default view that people with strong opposing beliefs are one’s enemies, adding “we need to de-escalate these things”. Read more via the Guardian