Pope Benedict is promising "unconditional reverence and obedience" to his successor.
Benedict delivered his final greetings to cardinals at the Vatican today before he retires in just a few hours.
Benedict urged them to work in unity so that the College of Cardinals is "like an orchestra" where "agreement and harmony" can be reached.
At about 9 a.m. Colorado time, the Pope will take a helicopter to the papal retreat south of Rome.
