Altar servers are pictured as Pope Francis celebrates a Mass in the Zairean rite for the Congolese community in St. Peter's Basilica at the Vatican in this Dec. 1, 2019, file photo. In the preface to a new book, the pope said the approval of the Zairean rite of the Roman Missal shows that it's also possible to develop a rite for the Amazon region. (CNS photo/Vatican Media)