Revd Brian Anderson led the service for Adrian "Izzy" Ismay, a 52-year-old father of three who died after being injured in a dissident republican bomb attack.
Hundreds of family, friends and colleagues gathered in Belfast to say farewell to him.
Revd Anderson, told the congregation that the dark act which took Mr Ismay's life was in stark contrast to the light the Cumbrian-born Falklands veteran brought to so many.
"In the darkest part of night, probably dressed in dark clothes, dark men did a dark, dark deed, bringing us to this place today, leading to the loss of Izzy, causing us to travel through the valley of the shadow of death," he said.
He said the funeral provided a platform to send a strong message to those still intent on violence.
"It gives me the opportunity to voice the opinion and the thoughts of the overwhelming number of people across our country to say we reject what you have done, we stand against what you have done, we want to build an inclusive peaceful society in Northern Ireland and your contribution to it we do not want," he said.
"It's incumbent upon us as a society to ensure that those men who represent a time in our past don't get any fuel and we want them to go away and it's up to us at all levels of society to ensure we build a society that does not want them, does not need them and rejects them utterly."
Mr Ismay served in the Royal Navy, seeing action in the Falklands War, before joining the Northern Ireland Prison Service in 1987. Away from his job as a trainer of new recruits to the service, he was heavily involved in volunteering work with the Scouts, St John Ambulance and Community Rescue Service.
He died 11 days after suffering serious leg injuries when a bomb exploded underneath his van as he drove to work from his east Belfast home.
A dissident republican group calling itself the New IRA, which opposes the Northern Ireland peace process, claimed to have carried out the attack on the long-serving officer.
As the funeral took place in Woodvale Methodist Church off the Shankill Road, hundreds gathered in Belfast city centre for a public vigil for the officer.
A host of dignitaries joined Mr Ismay's wife, Sharon, and three daughters, Samantha, Sarah and Tori, at the funeral service.
Northern Ireland Secretary Theresa Villiers, Stormont First Minister Arlene Foster and Justice Minister David Ford attended, as did Police Service of Northern Ireland (PSNI) Chief Constable George Hamilton and NI Prison Service director-general Sue McAllister.
The Irish Government was represented by the Department of Justice's acting secretary- general, Noel Watters.