Hamel, 86, was killed while giving Mass on Tuesday in the town of Saint-Etienne-du-Rouvray in northern France, in an attack that was later claimed by the Islamic State (IS) group.
The two assailants took two nuns and two parishioners hostage before being shot dead by police officers responding to the terror incident.
The moving gathering at Notre-Dame was a rare show of unity and respite from days of political sniping over repeated attacks on French soil, which right-wing parties say are due to the Socialist government's failure to protect citizens.
The Mass was attended by leaders of France’s Muslim, Jewish and protestant communities.
"Those who drape themselves in the finery of religion to hide their deadly project, those who tell us of a God of death, a Moloch (false god) who rejoices in the death of man and promises heaven to those that kill by invoking him. They cannot hope that man gives in to their illusion," said Cardinal André Vingt-Trois at the service.
The Mass came after a meeting earlier in the day between Hollande and top religious leaders who warned French people against being drawn in by the IS group’s efforts to pit different believers against each other.
Prime Minister Manuel Valls has warned that the goal of the attack was to "set the French people against each other, attack religion in order to start a war of religions".
In an editorial, Le Monde newspaper wrote that France was under attack as it had one of the biggest Muslim communities in Europe.
"The jihadists' aim is to provoke violent revenge attacks that will create a religious war in our country," it said.
Police cancel march
Meanwhile, residents of Saint-Etienne-du-Rouvray were struggling to come to terms with the bloodshed in their small town.
They made their way to a makeshift memorial to lay flowers, candles and messages of peace – a ritual that has become chillingly familiar from Brussels and Paris to Nice and Munich, all cities that have been struck by attackers inspired by the IS group.
The government, already under pressure after the Nice attack, faced more questions over security weaknesses after it emerged that one of the two assailants who stormed the church was known to anti-terror investigators.
Citing security concerns, the regional police prefect decided to cancel a silent march through the streets of Saint-Etienne-du-Rouvray in memory of Father Hamel, which had been planned for Thursday.
A gathering to pay tribute to the slain priest was to take place in a nearby sports park instead.
(FRANCE 24 with AFP)
Date created : 2016-07-27