[4] Auza was ordained a priest by Bishop Daniel Francis Walsh of the Roman Catholic Diocese of Santa Rosa in California on 29 June 1985.

At the Pontifical University of Saint Thomas Aquinas (Angelicum), he obtained a Licentiate in Canon Law in 1989 and a Doctorate in Sacred Theology in 1990.

[6] On 16 July, his responsibilities were expanded to include the role of Permanent Observer to the Organization of American States (OAS).

[7] In October 2014 Auza called for a broad definition of the term “rule of law” that includes respect, dignity, and justice.

This definition, with its reference point in the natural law, sidesteps self-referential definitional frameworks and anchors the orientation of the rule of law within the ultimate and essential goal of all law, namely to promote and guarantee the dignity of the human person and the common good.”[8] In the same speech, he noted the Vatican’s hope that “the alarming, escalating phenomenon of international terrorism, new in some of its expressions and utterly ruthless in its barbarity, be an occasion for a deeper and more urgent study on how to re-enforce the international juridical framework of a multilateral application of our common responsibility to protect people from all forms of unjust aggression.”[9] His assignment to the OAS ended on 31 August 2019.