Pope Saint Gregory VII

Now, my dearest brothers, listen carefully to what I tell you. All those throughout the world who are numbered as Christian and who truly acknowledge the Christian faith know and believe that the blessed Peter, the prince of the apostles, is the father of all Christians and, after Christ, the first shepherd, and that the holy Roman Church is the mother and teacher of all the churches. Therefore, if you believe this and hold to it without hesitation, I ask you and enjoin upon you by Almighty God – I your brother and unworthy teacher as I am – to support and assist your father and your mother if you wish to have, through them, the remission of all your sins, along with blessings and grace in this world and in the life to come. May almighty God, from whom all good things come, continually enlighten your minds and fill them with love for him and for your neighbor, so that by your devotion you may deserve to make this father and mother of whom I have spoken your debtors and enter without shame into their company. Amen.

-- Pope Saint Gregory VII from a letter