Aviz was ordained a priest 26 November 1972. He began his ministry as a parish priest in the diocese of Apucarana, as Rector of the Major Seminary Apucarana and Londrina, and as professor of dogmatic theology at the Theological Institute Paul VI in Londrina. He was also member of the Council of Priests and the College of Consultors and General Coordinator of the Diocesan Pastoral Apucarana. As a young priest Aviz was once on his way to a village to say Mass when he stumbled upon an armored car robbery. He was caught in the crossfire and shot, with bullets perforating his lungs and intestines and one eye. He survived and surgeons were able to save his eye; he still carries fragments of those bullets in his body.
On 4 January 2011, Aviz, not a member of a religious order, was appointed prefect of the Congregation for Institutes of Consecrated Life and Societies of Apostolic Life. He is the fourth Brazilian to head a Vatican department. In February 2011, Aviz said he almost abandoned the seminary and the Catholic Church because of the ideological excesses that emerged in the early years of liberation theology. He said in an interview that "Personally, I lived with a lot of anguish during the years of the birth of liberation theology". He said he appreciated that liberation theology promoted the preferential option for the poor, which represents "the church's sincere and responsible concern for the vast phenomenon of social exclusion." He said consecrated men and womenneed to explore more deeply the mystery of God to strengthen their relationships with others. In July 2011, he referred to a breakdown in trust between the Vatican and many religious orders because of "some positions taken previously", referring to his predecessor, Cardinal Franc Rode, who decried a "crisis" in religious life following the Second Vatican Council which he believed to have fostered excessively liberalizing currents in some communities of religious. Braz said that he recognizes there are problems, but his main aim is to "rebuild trust" by approaching issues in a new way, "without preemptive condemnations" and "by listening to people's concerns." Pope Benedict made him a cardinal on 18 February 2012, with the rank of Cardinal-Deacon assigned to Sant'Elena fuori Porta Prenestina. On 21 April 2012 he was appointed a member of the Congregation for the Clergy and the Congregation for Catholic Education. In the spring of 2013, at the time of the conclave that elected Pope Francis, he was mentioned as a possible candidate for election to the papacy. On 16 December 2013, Pope Francis named him a member of the Congregation for Bishops.
