Pope Benedict XVI has promised "unconditional reverence and obedience" to his successor in his final greetings to cardinals before retiring.
Benedict urged his cardinals on Thursday to work in unity and said he would pray for them in as they choose his successor.
This Evening, Benedict will leave the palace for the last time as pontiff.
At that point, Benedict becomes the first pontiff in 600 years to resign.
The Roman Catholic Diocese of Providence will mark the final day with a mass at the cathedral of Saints Peter and Paul at noon Thursday.
Providence Bishop Thomas Tobin calls the resignation an act of great humility.
