A woman holds a candle with a picture of Pope John Paul II as she commemorates the ninth anniversary of his death in Wadowice, the birth place of the Polish pope, April 2, 2014. Pope John Paul II will be canonized during a celebration mass led by Pope Fra
A woman holds a candle with a picture of Pope John Paul II as she commemorates the ninth anniversary of his death in Wadowice, the birth place of the Polish pope, April 2, 2014. Pope John Paul II will be canonized during a celebration mass led by Pope Francis, the current pope of the Catholic church, on April 27. REUTERS/Kacper Pempel REUTERS/Kacper Pempel

Humility and simplicity are Pope Francis' leadership mantras ever since accepting the post as supreme Pontiff of the Roman Catholic Church. These should no longer come as a surprise on the set April 27 canonization of Popes John Paul II and John XXIII.

According to Cardinal Agostino Vallini, vicar of Rome, churches in Rome's center have been instructed to remain open overnight before the canonization to give pilgrims a spiritual retreat. Apart from the "not much else" has been planned and laid out for the canonization, a milestone for the Roman Catholic church because this is the first the Vatican will be holding a double canonization of the two former popes.

The April 27 saint-making ceremony has been deliberately toned down, if it were to be compared with the three-day extravaganza that accompanied John Paul's beatification in 2011.

Three years ago, preparations for John Paul's beatification included a prayer vigil on Rome's Circus Maximus field for tens of thousands of people. The vigil cost the Church more than the budget allotted of $1.65 million. Around 1.5 million people watched the beatification mass, according to Rome police. Some 14 giant TV screens were set up for the event.

"What's important that happens is that there's a sobriety to get to the essential," Monsignor Walter Insero, Cardinal Vallini's communications director, said of the double canonization.

Read: Vatican Double Pope Sainthoods: A Massive Online Social Media Celebration

Italian media forecast as high as seven million people will flock to the event on April 27.

Rev. Federico Lombardi, in an attempt to downplay the event, said only 250,000 people can fit in St. Peter's Square and the main boulevard leading to it.