Diocese of Balanga/1975–1998: Celso Nogoy Guevarra

On March 17, 1975, the same date as the Diocese of San Fernando in Pampanga was elevated to an archdiocese on which Bataan was then under from, the Diocese of Balanga was created by Pope Paul VI. On June 4 of that same year, Bishop Celso Nogoy Guevarra was appointed and five months later on November 8, he became the diocese's first bishop upon installation, marking its canonical erection and separation of Bataan from the ecclesiastical territory of Pampanga. With this, the Parish of St. Joseph under the archdiocese became a cathedral now named as Cathedral-Parish of St. Joseph. Guevarra is the longest serving Bishop of Balanga, serving for 24 calendar years and 8,258 days from November 8, 1975 to June 18, 1998. He oversaw the improvement of Balanga Cathedral's facade in 1995 by placing bricks on it.

During Guevarra's tenure, Orani Church, under the patronage of Virgen Milagrosa de Orani which is also the Diocese of Balanga's patroness, became the first diocesan shrine and remain the only shrine in the diocese until the declaration of Lamao Church (Parish of St. Roche) in Limay on August 16, 2014 under the tenure of Bishop Ruperto Cruz Santos and Rev. Fr. Percival Medina as rector and parish priest.

On April 8, 1998, Pope John Paul II accepted Guevarra's resignation due to age, with it became effective on June 18 of that year upon his successor Bishop Honesto Flores Ongtioco became the second bishop which ended his tenure as Bishop of Balanga.