The gathering, which will take place Feb. 21-24, 2019, is focused on the protection of minors from sexual abuse within the Church. The pope has asked the presidents of the world's bishops' conferences, and the heads of the Eastern Catholic Churches, to attend.
The bishops were also asked to answer by January 15 a questionnaire attached to the letter for use in internal preparations. Sharing information in advance is meant to facilitate, the letter says, the expression of opinions "constructively and critically," and to get a full picture of the current situation to see where reform is most needed.
The letter also expresses Pope Francis' thanks for the support of the bishops and his view that "collegial cooperation" is what will help them to tackle the challenges the Church is facing.
The letter concludes by saying that "each of us needs to own this challenge, coming together in solidarity, humility, and penitence to repair the damage done, sharing a common commitment to transparency, and holding everyone in the Church accountable."
The letter is signed by the summit's organizing committee, which is made up of members nominated by Pope Francis in November: Cardinal Blase Cupich of Chicago, Cardinal Oswald Gracias of Bombay, Archbishop Charles Scicluna of Malta, and Fr. Hans Zollner.
Papal spokesman Greg Burke said about the letter Dec. 18 that organizers are asking bishops to meet with victims in their own countries before February as "a concrete way of putting victims first, and acknowledging the horror of what happened."