In Colombia, a new hashtag is trending on Twitter: #theLastDayofWar. It refers to Thursday, June 23rd, the date when, after 52 years of blood-curdling violence, the Colombian Government finally signed a ceasefire with the world’s largest terrorist group, the FARC or Revolutionary Armed Forces of Colombia.

The news sparked nationwide celebrations as Colombians, radiant with joy, waving red, blue and yellow flags partied in the streets.

Yet the Church, a key player in the peace process, has given the ceasefire a more cautious welcome.

The Archbishop of Tunja, Luis Augusto Castro, who is president of Colombia’s Bishops’s Conference, hailed the agreement as “enormous progress” but stressed that it was only “part one” of Colombia’s drawn-out journey to freedom from violence.

“It is one thing to stop war,” he said, “it is quite another to build peace.”

Already, as the FARC and the Colombian Government thrash out final nuances of a six-point peace treaty in Havana, the Church is  looking ahead to the post-conflict era.

“We hope to take a full and active part in building the new Colombia,” said Castro, referring to the social legacy of a half-century of war that has left 225,000 dead, six million forcibly evicted from their land, and thousands more traumatised by a bloody cycle of murders, kidnapping, rape and torture.

Building the new Colombia “will be like starting a house from scratch,” said Castro, who adds: “The cement will be ethics – there is so much corruption here – and spiritual renewal, by which I mean forgiveness and reconciliation.”

Castro said Colombia now needs a politics based on “the rock of the Gospel,” meaning one that broadens participation, as well as “an economy that addresses the needs of the poor.” He is encouraging all Colombians “to build the new Colombia together.”

“Peace” he emphasizes, “is a task for everyone.”

It is not an easy sell, in part because a section of Colombian society views the Havana peace dialogues as a sell-out.

Former premier Alvaro Uribe has accused the current president, Juan Manuel Santos, of surrender to the FARC which he says plans to turn Colombia into another Cuba.

The success of the peace treaty, which Santos hopes to sign off on July 20, will depend on the goodwill of the Colombian people, argues Father Dario Echeverri, secretary of the National Commission of Reconcilation.

“International observers have largely ignored the fact that the work of civil society in each region of Colombia will prove decisive in implementing the peace treaty. If people don’t get on board locally there won’t be peace,” he told me.

A seasoned intermediary who has spent many nights sleeping on the edge of the Amazon to negotiate with guerrilla groups for the release of kidnapped victims, Echeverri is acutely aware that social inequality is a root cause of the war.

“The Colombian war has a very different look in each region,” he explains. “In the Pacific, it affects the poor Afro-Colombians and indigenous peoples. In the South, the conflict has impacted poor farmers.”

Will they have a stake in the “new Colombia?”

Santos wants the country to vote on the peace negotiated with the FARC via a plebiscite; the guerrillas are less keen, though they have consented to the matter being settled in Colombia’s Constitutional Court. The country tops polls for inequality among the richer Latin nations. This injustice has long proved a rallying cry and justification for FARC violence.

“Some Colombians live a First World lifestyle of foreign holidays, fine dining and expensive cars. Just miles away live others in a Third-World existence of hunger, little education or access to public services,” says Claudia Palacios, the author of Perdonar Lo Imperdonable (“Forgiving the Unforgivable”) a book that collates testimonies from ex-FARC fighters, their victims, and former paramilitaries or members of the right-wing self-defense groups funded by the wealthy but disbanded in 2005.

With tales of ex-FARC fighters turned waiters begging forgiveness from the bosses whose kidnappings they once helped to plan, Palacios’ book gives concrete examples of how “Colombians are already making peace with each other on a daily basis.”

“Peace,” she says, “is not just a piece of paper.”

The Church has played a key role in rebuilding trust between former enemies. In 2014, it was invited by both FARC and Government to mediate on their behalf with the eight million registered victims of the conflict.

The true number of those affected by the war “is closer to 24 million, if you take into account that for every victim, two other people close to the victim are affected too,” estimates Castro. “We in the Church support peace because we value life that has been degraded and trampled upon in Colombia.”

At his instigation, the Church brought 60 of those victims to Havana to tell their stories during the peace talks.

“We thought it made no sense to include victims on the agenda and not listen to them,” he explained. The experience proved cathartic. “Each victim thought that they perhaps had been the worst treated of all, but began to modify that view on hearing the stories of the others.”

Around 15 per cent of the Colombian population has been impacted by the war. Some victims have joined the FARC or the right-wing paramilitary groups to avenge the death of their loved ones. According to a 2014 study, 79 per cent of all murders in Colombia are motivated by revenge.

“A high proportion of perpetrators of violence are victims themselves who have never been taught how to deal with rage and overcome their desire for revenge,” observes Father Leonel Narvaez, who for 20 years has led workshops in forgiveness for victims.

The deal worked out in Havana is testing that capacity to forgive. The Transitional Justice for the crimes of War proposed in Havana offers war criminals lighter sentences – ranging from five to eight years – for early confessions of guilt should they also proffer redress for their victims.

Rather than punishment, the accent is on restorative justice:  reintegrating former guerrillas into society, so they have a stake and want to belong.

Does forgiveness mean allowing war criminals to escape punishment? Castro’s message is that forgiving is about setting the victim free from their own pain.

“Forgiveness is a gift a victim can give him or herself that does not depend on obtaining justice first,” he said. “It doesn’t mean covering up injustice – the peace process is more about justice than anything else.” But forgiveness “restores to the victim the dignity that violence has stolen from them.”

As evidence, he cites the fruits of the victim meetings in Havana. One woman who spoke had seen 48 members of her family die at the hands of the FARC. After hearing her story, the FARC delegate embraced her and begged for forgiveness. She wept.

Only on the basis of such acts of reconciliation will Colombia’s peace be effective, which is why the Church’s role in providing space and encouragement for forgiveness has been so crucial.

There can be few better illustrations of the Church as a field hospital and the power of God’s mercy than a Colombia that finds peace. And a papal visit early next year could be one of its rewards.