Julio Lizares Labayen Jr. was born on 23 July 1926, at 1:25 AM at Talisay City, Negros Occidental. He is the third child of nine children (eight boys and one girl) born from Julio Diaz Labayen Sr. and Mercedes Labayen (née Mercedes Alunan Lizares). He was baptized at the San Nicolas de Tolentino Parish in the same city he was born on 2 April 1927 and was confirmed 19 May of the same year.

The Labayen family transferred to Bacolod City three years after Nonoy's (Julio Jr.'s nickname) birth. It is in this city that he will finish his elementary education. Afterwards, he studied his secondary education at Negros Occidental High School from 1938-1941, only to be interrupted by the closing of schools due to the outset of the Second World War. He graduated from high school in 1944.

The Japanese occupation during the Second World War, despite its horrendous effects, also brought the leader within the young Julio Jr. To distract the minds of the young people from the war, he organized together with his siblings and friends a basketball league in their neighborhood. Nonoy would earn the monicker "Scoring Machine" for his prowess in playing basketball.

Julio Jr. had his first communion on 1933. This made a big impact on the young boy's life. He would eventually be an altar boy for Bishop Casimiro Lladoc and Fr. Antonio Fortich who later on became a bishop and a fellow critic of Marcos. At the time of his transfer to Iloilo, Nonoy would still serve in the Mass at the Assumption Convent and sometimes at the Carmelite Monastery. He would keep this stint until his entrance to Carmel at age 22.

His love for the Eucharist also brought him to join a youth group in his parish devoted to foster the devotion to Jesus' body in the form of bread. He also became a catechist in their parish.

Despite the usual attraction to the opposite sex during his youth, Julio Jr. felt called towards religious life. After high school, the young man approached his mother to ask permission to pursue this longing to be a priest. But his mother did not allow him, thinking that it was just a surge of emotions. She asked him to take first a two-year college program so that he could think and assess himself more. Julio Sr. wanted a doctor in his family - as such his son would pursue a pre-medicine course at the Colegio de San Agustin de Iloilo. There he would play for the school's basketball team and would herald a no-defeat record with his team.

He graduated in 1947 with an Associate of Arts degree in Preparatory Medicine. But still the call to priesthood continues to beckon the young man.

"Seeing he was dressed in full carmelite garb, to me, was love at first sight" was how Julio Jr. would describe his first meeting with Fr. Patrick Shanley, OCD, then the chaplain of USA Army. This meeting was arranged by the Carmelite nuns of Iloilo City where three young men, including Julio Jr., were considering entering the religious vocation. This instant attraction led Fr. Shanley, OCD to promise to the young man, to whom he has seen an ardent desire to enter the Order, that he would be communicating with him again in case he was accepted for the novitiate in the United States.

Meanwhile, Julio Jr. studied Latin in San Jose Seminary with the Society of Jesus for two years as the subject is a requisite for the seminary life. After a seemingly long wait of two years, the Washington Province of the Order of the Discalced Carmelites notified the three young men that they were accepted as novices in Brookline, Massachusetts in Boston. They began their arrived at the Monastery of the Espousal of Mary and Joseph on 15 October 1949, coinciding with the Carmelite Solemnity of Saint Teresa of Ávila.

On 6 November 1949, Julio Jr. received the brown habit of the Carmelites as a novice and took the religious name Br. Xavier. After the yearlong period of novitiate, he made his first Profession of Vows as a religious and would adopt the religious name Br. Xavier of the Immaculate Heart. His made his definitive profession, his Solemn Profession of Vows in Rome, Italy on 14 May 1953.

It was also in 1949 that Br. Xavier, OCD begun his studies on Bachelor's Degree in Philosophy at Holy Hill, Wisconsin where he graduated in 1952 as magna cum laude. Thereon, he transferred to Rome to study at the Teresianum to study Theology. Again, he finished his Master's Degree in Theology with flying colors as a cum laude on 1957. He then enrolled at Pontifical University of Saint Thomas Aquinas commonly known as the "Angelicum" to study Canon Law. Proving again his intellectual competence, he finished his Master's Degree in Canon Law, now as summa cum laude in 1959.

Together with five deacons, Adeodato Giovanni Cardinal Piazza ordained Rev. Xavier, OCD as a priest on 4 June 1955 in Rome, Italy. Due to his studies, he was only able to celebrate his thanksgiving mass in his hometown Bacolod City since he was ordained on 14 November 1959.

He returned to the Philippines at the behest of Bishop Patrick Shanley, OCD to join the Carmelite mission in Infanta, Quezon. It was at that he received his first assignment as the assistant parish priest of St. Joseph's Parish in Polillo, Quezon. After this short stint, he became the parish priest of the same parish on 1960.

In this short span of time, the worsening health condition of Bishop Shanley, OCD compelled the first bishop of Infanta to return to the United States. With this situation, the young Fr. Xavier, OCD, with a short pastoral experience, was appointed Apostolic Administrator of the Prelature on 23 June 1961.

During this time the Second Vatican Council was held in Rome. The ecumenical council, which was convened by Saint John XIII on 11 October 1962 and closed by Blessed Paul VI on 8 December 1965 that the Catholic Church gradually opened its doors to the people of the modern world. Erstwhile, in the Asian setting, getting wind of the changes already happening in Rome, the Jesuits organized a workshop on social action apostolate in Hong Kong on September 1965. Fr. Xavier, OCD attended the said workshop and at his return to the Philippines, he was asked by his fellow participants to convince the Catholic Bishops' Conference of the Philippines (CBCP) to organize the social apostolate arm of the local Church. With this, he was appointed to be the first national director of the National Secretariat for Social Action (NASSA) which was created in January 1966.

It was not surprising that the Holy See chose him to be the shepherd of the Prelature of Infanta eight months later.

The Church in the Philippines declared during the Second Plenary Council of the Philippines (informally known as the PCP-II convoked in 1991) that "As we approach the year 2000, Christ bids this community—ourselves, the laity, religious and clergy of the Catholic Church in the Philippines—to be a Church of the Poor." This vision, first arose during the Second Vatican Council, upholding Catholic social teachings, were adapted by local conferences such as the Episcopal Conference of Latin America (CELAM) when they declared the "preferential option for the poor" and the Federation of Asian Bishops' Conferences (FABC) declaring the same in 1975.

Long before the declaration of PCP-II, Bishop Labayen, OCD was an ardent proponent of the Church of the Poor in the Philippines which was his brainchild in the Prelature of Infanta. He became its servant leader and shepherd as he launched the program Church of the Poor in the prelature in 1979. The program prioritized to serve those neglected by the society: workers, indigenous people and others who relied on no one but themselves. As a shepherd, he immersed himself with the people and established dialogue in the grassroots, a concept the laity never imagined to happen. As such he became close to the heart of the people who loved him as a father.

With the Church's regulations on mandatory retirement when bishops step on age 75, Bishop Labayen, OCD submitted his retirement letter to the Holy See. But still he was ask to wait for his successor as the bishop prelate. On 28 June 2003, he was formally relieved of his duties and was replaced by his Carmelite confrere, Bishop Rolando Tirona, then occupying the see of Malolos. Bishop Labayen, OCD was 57 years a priest, 42 years as bishop and 75 years of age at his retirement. After his retirement, he occasionally still visited the Bahay-Kubo as he calls the bishop's residence, until his health stopped him from doing so. This raised criticism from people, but he explained that retirement is only to "re-tire" or to change tires, towards a renewed vigor of service. As such, the bishop was still prolific in his social advocacies even in his retirement.

Years after, he spent his last years in Antipolo City, Rizal being taken care of one of the congregations he founded.

Bishop Labayen, OCD died on 27 April 2016 at 6:52 AM. People poured from different walks of life during his wake in different locations: first in Quezon City, then to Baler, Aurora, and after to Infanta, Quezon. His remains was returned to his retirement place in Antipolo City where he was buried in a crypt under the congregation's chapel on 3 May 2016.