Theology head the Rev Associate Prof Christopher Holmes said the service was a way to honour what had been done at the university over the past three-quarters of a century.
"We are really grateful that we are not just here, but we’re thriving," Prof Holmes said.
"Part of our celebration [last night] is to emphasise the really good and positive things that have been happening in the programme."
The Christian faith was embraced by a significant minority in New Zealand, he said.
And there was a diverse group of churches spread across the country.
"I think it’s important to recognise that the Christian church in New Zealand is actually a significant presence.
"It is amongst people who have been here a long time, amongst indigenous peoples, amongst new New Zealanders ... amongst Pacific peoples".
The theology programme at Otago began as a combined effort between the Presbyterian Church of Aotearoa New Zealand and the Roman Catholic Church, he said.
Church dignitaries from both were at the celebrations last night.
Short speeches, highlighting reasons for giving thanks for the programme, accompanied words from Knox Church minister the Rev Dr Kerry Enright.
Prof Holmes said the university offered theological education at an undergraduate and postgraduate level to students all over the country.
