In 1935 del Portillo joined Opus Dei, which had been founded by St. Josemaría Escrivá seven years before. In keeping with his vocation to Opus Dei, he sought to sanctify his professional work and daily duties, and he carried out a broad apostolate with his classmates and colleagues. He would soon become St. Josemaría’s strongest support, which he remained for almost forty years.
On June 25, 1944, del Portillo was ordained as one of the first 3 priests of Opus Dei. From then on he dedicated himself to pastoral ministry, serving the members of Opus Dei and many others. In 1946 he moved to Rome with St. Josemaría, where he served on Opus Dei’s General Council until 1975.
During Fr. del Portillo’s years in Rome, the Holy See entrusted a number of tasks to him, and he carried these out with great dedication. He was a consultor to several congregations and councils of the Holy See, such as the Congregation for the Doctrine of the Faith, the Congregation for the Clergy, the Congregation for the Causes of Saints, and the Pontifical Council for Social Communications. He took part in the Second Vatican Council in various capacities, first as head of the ante-preparatory Commission on the Laity and then as secretary to the Commission on the Discipline of the Clergy, and also as a consultor to other commissions. His books Faithful and Laity in the Church (1969) and On the Priesthood (1970) are largely the fruit of that experience. As a member of the Commission for the Revision of the Code of Canon Law, he also helped draft the current Code, promulgated by John Paul II in 1983.
On September 15, 1975, Fr. del Portillo was elected as St. Josemaría’s first successor. When Opus Dei was established as a personal prelature on November 28, 1982, Pope John Paul II appointed him Prelate of Opus Dei. The Holy Father later ordained him as a bishop on January 6, 1991.
Bishop del Portillo worked diligently to serve the Church by extending the apostolates of Opus Dei, and his governance was characterized by great fidelity to St. Josemaría and his message. During his nineteen years at the head of Opus Dei, the work of the prelature started in twenty new countries.
His dedication to the mission he had received was rooted in a deep sense of his divine filiation, one of St. Josemaría’s key teachings. This led him to seek identification with Christ in a spirit of trusting abandonment to the will of God the Father, nourished by prayer, the Eucharist, and devotion to Mary. His love for the Church was seen in his close communion with the Pope and the bishops. He had charity toward all, showed tireless concern for his daughters and sons in Opus Dei, and always spread kindness, serenity, and good humor around him. A spiritual portrait of his soul would also include his humility, prudence, fortitude, simplicity and selflessness. His zeal to win souls for Christ was reflected in his episcopal motto: Regnare Christum volumus! We want Christ to reign!
Early in the morning of March 23, 1994, God called his good and faithful servant to Himself. Bishop del Portillo had returned only a few hours before from a pilgrimage to the Holy Land, where, with deep prayer and piety, he had followed Jesus’ footsteps from Nazareth to the Holy Sepulcher. He had celebrated his last Mass on earth in the Church of the Cenacle in Jerusalem. Later that day, Pope John Paul II came to pray before Bishop del Portillo’s remains, which now lie in the crypt of the Church of the Prelature, Our Lady of Peace at Bruno Buozzi 75, Rome.