Members of the Langley Hill Friends Meeting, a peace group in northern Virginia to which Tom Fox belonged, read a statement he co-wrote in October 2004 in which he shunned any form of violence, including attempts to rescue him should he ever be kidnapped.
"We reject violence to punish anyone who harms us," said Doug Smith, quoting Fox, in a statement read to reporters at the group's headquarters in the town of McLean in Virginia.
"We forgive those who consider us their enemies," Fox's statement continued. "Therefore, any penalty should be in the spirit of restorative justice rather than in the form of violent retribution."
Evidence of torture
Fox, 54, was abducted in Baghdad in November along with three other members of the Chicago-based Christian Peacemaker Teams by a group calling itself the "Swords of Truth."
Iraqi police on Saturday reported the discovery of his body at a rubbish dump in western Baghdad, bound, shot and showing signs of torture.
While mourning the loss of Fox, the Langley Hill group urged people to remember the thousands of Iraqis and others around the world who were victims of violence.
"Such an outpouring of action for justice and peace would be a fitting memorial for Tom"
Christian Peacemaker Teams
"We at Langley Hill will honour Tom's courage by ensuring that the work to which he was dedicated continues and that all the stories of loss, not just Langley Hill's, are told," said Smith.
In a separate statement, Christian Peacemaker Teams said Fox's death "pierces us with pain," but urged Christians to speak against what it called the illegal detainment of thousands of Iraqis by US and British forces.
"Such an outpouring of action for justice and peace would be a fitting memorial for Tom," it said.
The group said it planned a vigil in downtown Chicago on Saturday night to honour the memory of Fox and pray for the release of its three members still being held in Iraq.
Fears about Fox's fate were raised earlier in the week when al Jazeera aired a video dated 28 February showing only fellow activists Norman Kember from the UK and Canadians James Loney and Harmeet Sooden.
There was no word on Saturday on the fate of the three, who looked well in the video and did not appear distressed.
More than 200 foreigners and thousands of Iraqis have been kidnapped since the 2003 U.S.-led invasion of Iraq. Fifty-four foreign hostages are known to have been killed by their captors.