Born in Bohol (Philippines), he was ordained a priest on 29 June 1985 at the Church of the Good Shepherd in Pittsburg, California. After High School at the Immaculate Heart of Mary Seminary in Tagbilaran City (Bohol), he took his studies at the Catholic University of Santo Tomas in Manila (1977-1986), at the Pontifical University of Saint Thomas in Rome (1986-90) and at the Vatican Diplomatic School (1987-90).
Archbishop Auza joined the diplomatic service of the Holy See in June 1990, serving in different capacities successively in Madagascar and Mauritius, Bulgaria, Albania, the Secretariat of State in the Vatican (1998-2006) and the Permanent Observer Mission of the Holy See to the United Nations in New York (2006-2008).
In May 2008, Pope Benedict named him Papal Nuncio to Haiti. He was consecrated an Archbishop on 3 July 2008 at Saint Peter’s Basilica in the Vatican.
In July 2014, Pope Francis appointed him Permanent Observer of the Holy See to the United Nations in New York and Permanent Observer of the Holy See to the Organization of American States in Washington, D.C. In these capacities, Archbishop Auza has led Delegations of the Holy See to international conferences and to negotiations for Treaties and Conventions.