On March 11, 1944, Obviar was appointed the first
auxiliary bishop of Lipa and titular bishop of
Linoë,
Turkey. He was subsequently ordained to the
episcopate on 29 June 1944, with the Apostolic delegate to the Philippines, Archbishop
Guglielmo Piani, as principal consecrator, with Pedro Paulo Santos,
Bishop of Caceres, and
Cesar Maria Guerrero, auxiliary bishop of Manila as co-consecrators. On 22 January 1951, Obviar was installed as
Apostolic administrator of the new
Diocese of Lucena. Motivated by his great work for
catechesis, he founded the Missionary Catechists of St. Therese (MCST) on August 12, 1958. He established the Missionary Catechists of Saint Thérèse of the Infant Jesus (MCST), with the help of Mother Mercy Medenilla, who became the first superior of the MCST, and has four other women. The earliest monastic MCST was founded in
San Narciso, Quezon. To compensate for the shortage of priests in the new diocese, Obviar also founded the Our Lady of the Most Holy Seminary which was later renamed as Our Lady of Mount Carmel Seminary, a minor seminary in Sariaya, Quezon. Decades after, a major seminary was founded by the Diocese of Lucena re-institutionalizing the name Our Lady of the Most Holy Rosary Seminary. The establishment of this increased the number of priests attending from 1951 to 1975. In the year of his retirement, it had increased by more than 100 priests. Obviar ordained
Ricardo Jamin Vidal to the priesthood on
St. Patrick's Day, 17 March 1956, in Lucena; Vidal would later become a
cardinal and Archbishop Emeritus of the
Archdiocese of Cebu. From 11 October 1962 to 8 December 1962, Obviar was a Council Father at the first session of the
Second Vatican Council. After more than 18 years as administrator, Obviar was declared the first
diocesan bishop of the Diocese of Lucena on July 15, 1969. He served as Bishop of Lucena until his retirement in 1976. ==Death==