The Roman Catholic Church and some Anglo-Catholics teach that, like baptism, confirmation marks the recipient permanently, making it impossible to receive the sacrament twice. It accepts as valid a confirmation conferred within churches, such as the Eastern Orthodox Church, whose Holy Orders it sees as valid through the apostolic succession of their bishops. But it considers it necessary to administer the sacrament of confirmation, in its view for the only time, to Protestants who are admitted to full communion with the Catholic Church.