Brian and Grace Johnston, killed in the Kenya road crash, were due to become grandparents again in a four to five days' time.
Pastor John Elen, of Greerton Bible Church, told the Bay of Plenty Times, members were struggling to come to terms with their loss.
The Johnstons had been part of the church family for about 25 years and news of their deaths had hit the group especially hard.
"Greerton Bible Church is very much a family and when one hurts, we all hurt. There's a lot of hurting people out there," Pastor Elen said.
"One lady said she had wept continuously all day. Another guy rang ... he didn't want to be alone."
The church held its own prayer service and vigil last night as a way to help congregation members grieve.
A live phone call feed with a Johnston family friend who knew Grace Johnston's Ireland-based parents was also arranged.
"So you can see she wasn't just a mum and grandmum. She was someone's daughter and sister," Pastor Elen said.
He also said that Mr Johnston had "an incredibly dry Irish sense of humour".
"It's heartbreaking. They do leave a big hole in so many ways.
"They were part of the family and they are not here anymore.
"We are going to miss them greatly," he said.
Pastor Elen said while the church was confident the Johnstons were now with their Lord, they also left behind not only the church family but their 10 children and their grandchildren.
"They have another grandchild due to be born in four to five days' time. That's a whole generation going to grow up not knowing their incredible grandparents," the pastor said.
Service details for the Johnstons and former Bethlehem College student Caitlin Dickson are yet to be announced.
A spokeswoman for the Ministry of Foreign Affairs and Trade said a time line for return to New Zealand was yet to be confirmed as each person killed must go through a repatriation process, which varied from country to country.
The Deputy High Commissioner from the New Zealand High Commission in Pretoria and the Consul from the New Zealand Embassy in Cairo were to arrive in Kisumu last night to provide on-going support and advice to the college group.
Foreign ministry officials would not release further details as families of the school group have requested privacy.