"Māori spiritual beliefs preceded the arrival of Europeans and Christianity, and other faith traditions from overseas soon followed," he said.
"While Christianity has been the dominant faith tradition since colonial days, its position has been eroding."
The Pew Research centre is predicting that by 2050, the proportion of Christians in New Zealand would slump from the current 57 per cent of the population to 44.7 per cent.
Ward said the increasing diversity made some uncomfortable.
On March 22, the Islamic call to prayer was broadcast over television, radio and inside mosques and Prime Minister Ardern said New Zealanders were encouraged to join in wherever they were.
He said Christians had more in common with Muslims than with followers of many other religions.
"As Jews, Christians and Muslims, we all worship the same God, the God of Abraham," Ward said.
"Muslims also recognise Jesus as a prophet and accept us as 'People of the Book'."
He said the phrase "Allahu Akbar" - used in the opening to the Muslim call to prayer meaning "God is great" - was also used in Palestinian churches.
"It is not our job to judge and exclude our Muslim brothers and sisters, or for that matter, anyone else because they worship God differently from us," Ward said.
"Jesus gave us two simple commandments; to love God and to love others. He also made it quite clear that it is through helping those in need that one gains eternal life."
He said after the events of Christchurch, many Muslims would be scared. Many had fled terror in their homelands thinking their new home was going to be safe.
"If we are to be true and faithful followers of Jesus the Christ, we should be showing love and compassion to our Muslim brothers and sisters, because right now they really need it," Ward added.
The Destiny group's actions have also attracted criticism on social media forums, including by Green MP Catherine Delahunty.