Papal Election to Follow Final Mass as World Awaits New Pope

On Tuesday, Catholic cardinals gathered for the last Mass before they retire behind the closed doors of the Sistine Chapel as they discuss and deliberate who will lead the world's 1.2 billion Catholics.

Cardinal Angelo Sodano, dean of the College of Cardinals, led the 115 cardinals during Tuesday's Mass in St. Peter's Basilica and called for unity in a Church that has recently been marred by divisive figures and explosive allegations.

"Each of us is therefore called to cooperate with the Successor of Peter, the visible foundation of such an ecclesial unity," Cardinal Sodano said. He added that the new pope has to "tirelessly promote justice and peace."

After Mass, the cardinals will take the short walk to the Sistine Chapel singing the Litany of Saints, which is a long-standing tradition concerning the intercession of saints in their quest to select a new pope.

The cardinals also will also hear a meditation by an elderly Maltese cardinal and take a sworn oath of secrecy, before being locked inside the chapel, where they are expected to cast their first ballots.

Should the cardinals cast their first ballots on Tuesday, puffs of smoke will be able to be seen from the chapel's chimney, with black smoke signaling a failed vote and white smoke for when a pope has been chosen. All of the cardinal's ballots are destroyed to maintain the integrity of the conclave.

Cardinals held their final closed-door debate on Monday to discuss what type of pope the Church needs at this time, with speculation that this will be a long, drawn out process.

"This time around, there are many different candidates, so it's normal that it's going to take longer than the last time," Cardinal Francisco Javier Errazuriz of Chile told AP.

"There are no groups, no compromises, no alliances, just each one with his conscience voting for the person he thinks is best, which is why I don't think it will be over quickly," he added.