The family of US journalist Steven Sotloff have spoken publicly for the first time since a video of his beheading was released by militants.
They said that the reporter gave his life to covering the suffering of people in war zones, but was "no hero".
Mr Sotloff "tried to find good concealed in a world of darkness".
Vice President Joe Biden said that Islamic State militants who killed him and another US man, James Foley, would be pursued "to the gates of hell".
Speaking at a press conference in Florida, Sotloff family spokesman Barak Barfi said that Steven "wanted to give voice to those who had none".
He said that Mr Sotloff "was no war junkie and did not want to be a modern-day Lawrence of Arabia".
"From the Libyan doctor in Misrata who struggled to provide psychological services to children ravaged by war, to the Syrian plumber who risked his life by crossing regime lines to purchase medicine, their story was Steve's story. He ultimately sacrificed his life to bring their story to the world," Mr Barfi said.
"Today we grieve but we will emerge stronger. We will not allow our enemies to hold us hostage with the sole weapon they possess: Fear."
Mr Barfi said that Steven Sotloff was "torn between two poles" - his love of home life and his passion for the Arab world.
He said that the Sotloff family's prayers went out to the family of Jim Foley - another American journalist who was similarly killed last month.
"Like Steve he suffered but his jailors never broke him. He was an inspiration to others held in prison."
'Degrade and destroy'
The tribute to Mr Sotloff came after President Barack Obama vowed that the US would not be intimidated following the release of a video tape of his murder by Islamic State (IS) militants.
Mr Obama said the US would build a coalition to "degrade and destroy" IS.
Vice-President Biden said that the US would not stop until the militants are brought to justice.
He said the American people "are so much stronger, so much more resolved" than any enemy can understand.
Next to a masked figure, Mr Sotloff reads out a text addressed to President Obama saying: "You've spent billions of US taxpayers' dollars and we have lost thousands of our troops in our previous fighting against the Islamic State, so where is the people's interest in reigniting this war?"
The militant spoke with a British accent similar to that of the man who appeared to carry out the beheading of James Foley.
He also threatens to kill the British hostage shown in the footage. The family of the British hostage have asked the media not to release his name.
IS has seized large swathes of territory in Iraq and Syria in recent months, declaring a new caliphate, or Islamic state, under leader Abu Bakr al-Baghdadi.
The US has launched more than 120 air strikes in the past month to try to help Kurdish forces curb the IS advance.