Millions of people are expected to visit Rome on December 8th, when Pope Francis' Holy Year of Mercy begins.
It's a year which encourages believers to reflect on God's mercy towards them, and how they can reflect that mercy to other people.
Islamic State has issued several death threats against the Vatican and specifically Pope Francis, and fears are heightened after Friday's terror attacks in Paris where at least 129 people have died.
The militant group claimed responsibility for the massacres.
For the first time since the practice of Holy Years began in the Catholic Church in 1300, pilgrims will have to register online and go through security checks.
Austen Ivereigh, director of Catholic Voices, told Premier: "They're not going to be cowed by this. Threats have existed for some time, threats specifically against the Pope.
"Security's extremely tight at the Vatican, much tighter than it's been for many, many years, but they're not going to allow this to disturb the normal rhythm of events.
"The Vatican takes security of pilgrims very, very seriously and it has to, because there'd be nothing worse than for a disaster of this sort to happen when there are thousands of pilgrims gathered in the square, but it is about finding a balance.
"Everybody wants to put him in a bulletproof glass box, and the Pope says 'look, I'm sorry, but when you go and see a friend, you don't go and visit them in a glass box - I have to be able to have contact with people'.
"That is the compromise. That is balance that he's striking."
Listen to Premier's Aaron James speaking to Austen Ivereigh here:
