She was killed outside her constituency office in Batley and Spen in west Yorkshire on Thursday.
Tearful tributes have been paid after it emerged her last words after being shot and stabbed in the street were "my pain is too much".
Speaking in Liverpool, Christian peer, Lord David Alton of Liverpool (pictured), said that Ms Cox had been dedicated to humanitarian causes.
He said: "Having spent the past 37 years in Parliament - in one House or the other - and given her remarkable dedication to humanitarian causes, at the very outset I want to pay my respects to the memory of Jo Cox, Member of Parliament, who was murdered yesterday.
"Her husband Brendan, in a poignant tribute said their family and friends would redouble their efforts "to fight against the hate that killed Jo"
"At a time when politicians are so often reviled or despised just keep in mind what Brendan said about Jo: that "Jo believed in a better world and she fought for it every day of her life with energy and a zest for life that would exhaust most people"; that "Hate doesn't have a creed, race or religion" and that we must unite to contest "the hatred that killed her."
He was speaking during a Premier Lecture 'A Battle of Belief - a matter of life and death' in Liverpool.
So far more than £220,000 has been raised for charities supported by Jo Cox.
Friends of the late Labour politician are raising money to support the three charities "closest to her heart" and chosen by her family following her death.
They represent her campaigns as an MP to help civilians caught up in the Syrian war, to fight racism and extremism in Britain, and to help residents in her Batley and Spen constituency in West Yorkshire.
the space of around 15 hours after the fund was launched on Friday.
The charities are:
- The White Helmets - unarmed and neutral volunteer search and rescue workers in Syria who have saved more than 51,000 lives from under the rubble of the conflict
- HOPE not hate - which seeks to challenge and defeat the politics of hate and extremism in communities across Britain
- The Royal Voluntary Service - to support volunteers helping to combat loneliness in Mrs Cox's constituency
The vicar of Birstall has said the community is "stunned" after the death of Jo Cox as he opened a book of condolence.
On Friday, Revd Paul Knight opened a book of condolence as church members provided tea and a place for contemplation.
The vicar said: "We wanted to give people the opportunity to pass on their sympathies for Jo, who was obviously so much liked in this area.
"At this point people don't know what to do.
"So we're giving them the space and the opportunity to voice or express their concerns, and their disappointments and their hurt."
He added: "I think for the most part people are just stunned. Shocked but stunned.
"I do detect a little bit of difference today as people wake up and are maybe thinking it was almost like a dream, like a TV show. But this morning it was reality. This has actually happened in our community."
He said he knew Ms Cox, who was "bubbly, vivacious, enthusiastic and passionate about helping the people of this area".
Listen to Lord Alton's pay tribute to Jo Cox here: