"They will not be forgotten."
Every step taken to make staff safer was a tribute to those lost.
Peggy Noble and Leigh Cleveland were killed and colleague Lindy Curtis was injured when a gunman opened fire at their office on Monday last week.
Mr Boyle told those in attendance that Ms Curtis was "making progress, to the relief of family and colleagues".
He said the incident highlighted the work of public servants who had committed to helping others.
Workers on the front counter of Winz centres must have "empathy, sympathy and a commitment to people", he said.
Police officers, St John staff, Defence Force representatives and firefighters all turned out for the service, as well as several hundred locals. Prime Minister John Key and Labour leader David Cunliffe were also there.
Several Work and Income staff dressed in black to pay their respects to their fallen colleagues.
Ashburton District Mayor Angus McKay's message to the town was: "Continue to look out for each other."
He said the incident "does not represent who we are as a community", but rather what defined the community was its reaction, which the mayor said he was proud of.
Mr Cunliffe described the service as "moving, sombre, a coming together of the Ashburton community in grief around the families of Peggy, Leigh and Lindy".
Mr Key also said the service had been very moving.
"It's a very sad day for a tight-knit community. It's not the sort of thing you expect to happen anywhere in New Zealand, but you certainly don't expect it in a small town like Ashburton.
"You can see how close the community is and how much pain they're feeling." APNZ
