Satan is working to uncover the sins of bishops so that they will be visible and a cause of scandal, Pope Francis said during his homily at Mass on Tuesday.

"This is good to remember, in these times in which it seems that the Great Accuser has been unchained and is attacking bishops. True, we are all sinners, we bishops. He tries to uncover the sins, so they are visible, in order to scandalize the people. The Great Accuser, as he himself says to God in the first chapter of the Book of Job, 'roams the earth looking for someone to accuse'. A bishop's strength against the Great Accuser is prayer, that of Jesus and his own; and the humility of being chosen and remaining close to the people of God, without seeking an aristocratic life that removes this unction," the pope said Sept. 11 during his Mass at the chapel of the Vatican's Casa Santa Marta.

"Let us pray, today, for our bishops: for me, for those who are here, and for all the bishops throughout the world."

Francis preached on the day's Gospel, which was Luke's account of the choosing of the twelve apostles, and focused on the episcopacy.

Among those in attendance at the Mass were several member of the Council of Cardinals, including Cardinal Sean O'Malley of Boston; Cardinal Giuseppe Bertello, president of the Pontifical Commission for Vatican City State; and Cardinal Oswald Gracias of Bombay.

Bishops are called to be men of prayer, the pope said, calling prayer "a bishop's consolation in difficult times."

He also commended humility to bishops, saying that "the bishop who loves Jesus is not trying to climb a ladder, advancing his vocation as if it were a mere task or seeking a better placement or promotion."

Rather, "a bishop feels chosen, and has the certainty of being chosen. This drives him to speak with the Lord: 'You chose me, of little importance, a sinner.' He is humble, because he feels chosen and feels Jesus' gaze upon his whole being. This gives him strength."

Francis also said a bishop "cannot remain distant from the people, he cannot have attitudes which lead him to be distant from them; the bishop touches the people and lets himself be touched by the people. He does not try to find refuge with the powerful, with the elite: no. The elites criticize the bishop; while the people have an attitude of love towards the bishop, and have this – as it were – this special unction: which confirms the bishop in his vocation."