"Please, no armored doors in the Church, everything open," the 78-year-old pontiff told pilgrims in St Peter's square, Italy's AGI news agency reported.
"There are places in the world where doors should not be locked with a key. There are still some but there are also many where armored doors have become the norm.
"We must not surrender to the idea that we must apply this way of thinking to every aspect of our lives," Francis said.
"To do so to the Church would be terrible."
The pope did not explicitly refer to last week's attacks on Paris, which he has condemned as "inhuman."
His comments came in the context of intense discussion in Italy about the security of the Vatican and Rome, which are seen as potential targets for Islamist militants.
Francis's comments also had a spiritual significance -- he has urged the Church to keep its doors open to lapsed believers who are considering returning and to the hundreds of thousands of migrants arriving in Europe from Africa, the Middle East and South Asia.
Italy announced this week that it would close airspace over Rome to drones for the duration of the upcoming Catholic jubilee year, which is expected to bring more than a million extra visitors to the Italian capital.
The move reflects fears a remote-controlled aircraft could be used by Islamic State or other militant groups to stage a potentially spectacular attack on the home of the Catholic church.
Security has also been stepped up at airports and train stations and some 700 extra troops deployed in public spaces in Rome.
Individuals purporting to be Islamic State militants have made a number of threats against Rome on social media and in the group's propaganda outlets.
Italian officials say they take such statements seriously but that they have never received evidence of a credible, specific plot to bomb Rome, the Vatican or the Pope. —Agence France-Presse
source: gmanetwork.com
