Encounter with Christ & Missionary Zeal
Like St. Paul, Fr. Charles Heerey encountered Jesus Christ in a way that left him convinced he had been chosen to spend his life as a missionary of God's infinite love. This conviction became the driving force of his ministry, shaping his apostolic zeal and pastoral charity, deeply guided by Scripture — particularly Luke 4:18, the feeding of the five thousand (Matt. 14:14–21), and the parable of the Good Samaritan (Luke 10:25–37).

Early Missionary Assignments
His first mission assignment was as assistant priest at the Sacred Heart Catholic Mission in Calabar, where he distinguished himself with tireless concern for the sick, especially lepers, embodying Christ's compassion for the marginalized.

Seminary Leadership (1924)
In 1924, he was appointed Rector of the newly founded St. Paul's Junior and Senior Seminary at Igbariam, Onitsha. With zeal and devotion, he gave structure to the seminary, mapping out daily activities and academic programs for both junior and senior arms, laying the foundation for the training of future priests in Nigeria.

Episcopal Ordination (1927)
On 29 May 1927, Charles Heerey was ordained Coadjutor Bishop of Southern Nigeria.

First Catholic Secondary School (1931–1933)
On 21 May 1931, he became Bishop and Vicar Apostolic of Southern Nigeria. At that time, the Church had about 200 primary schools and no secondary schools. In 1933, Bishop Charles Heerey built and opened the first Catholic Secondary School east of the Niger — Christ the King College (C.K.C.), Onitsha — addressing its pioneer students: "I expect you to remain here to finish your course and pass the Senior Cambridge. I am giving you the best staff at my disposal and I hope that you will bring credit to the Church, the college and your country."

Founding Religious Institutes (1937 & 1943)
In 1937, he established the Sisters of the Immaculate Heart of Mary, Mother of Christ, dedicated to uplifting women, serving the poor, and providing education and healthcare with Christlike compassion. In 1943, he founded the Brothers of St. Peter Claver for education and pastoral work, later absorbed into the Marist Brothers in 1957.

Healthcare Ministry
Moved by compassion for the people of Southern Nigeria, Archbishop Heerey established eight pilot hospitals across his vast ecclesiastical territory, supported by a network of clinics and maternities in remote areas. Among them were St. Luke's Hospital (Anua, Akwa Ibom), Holy Rosary Hospital (Emekuku, Imo), Bishop Shanahan Hospital (Nsukka, Enugu), St. Charles Borromeo Hospital (Onitsha, Anambra), Holy Rosary Hospital (Onitsha, Anambra), Our Lady of Lourdes Hospital (Ihiala, Anambra), and St. Joseph's Hospital (Adazi, Anambra). His 1951 annual report to Rome noted ministry to 700 lepers in government settlements and 733 others under direct Catholic mission care. By 1956, he had established nine Catholic leper settlements, celebrating the Eucharist and administering sacraments with profound humility, often confirming lepers with his bare hands.

Appointed First Archbishop of Onitsha (1950)
On 17 June 1950, he was appointed the first Archbishop of Onitsha and Metropolitan of Eastern Nigeria — at that moment the youngest bishop in the entire world, a testimony to his extraordinary zeal and the confidence the Church placed in him.

Monastic & University Vision (1940s–1950s)
In the late 1940s and 1950s, Archbishop Heerey sent Fr. Michael Iwene Tansi (later Blessed Michael Cyprian Iwene Tansi) and Fr. Clement Ulogu to Mount St. Bernard Monastery in England, hoping to establish a Catholic monastery. He also worked passionately toward a Catholic University in Eastern Nigeria. Though neither project materialized in his lifetime, he humbly submitted to God's will, trusting in divine providence.

Education & Secondary Schools
Through his inspiration and initiative, over 90 Catholic secondary schools and teachers' training colleges for boys and girls were established across Eastern Nigeria, including the renowned College of Immaculate Conception (C.I.C.), Enugu; Holy Ghost College, Owerri; Stella Maris College, Port Harcourt; Queen of the Rosary College (Q.R.C.), Onitsha; and Holy Rosary College (H.R.C.), Enugu. By the time of his death in 1967, there were over 3,000 Catholic primary schools across the region.

Youth Apostolate
Archbishop Heerey promoted youth involvement in evangelization by establishing the Young Catholic Students (Y.C.S.), with the help of Mr. Gabriel Eze of Oba, empowering young people to live and spread the faith actively.

Empowering the Laity & Women (1965)
To encourage the active participation of women in the Church, he founded the Catholic Women Organisation (C.W.O.) in Onitsha in 1965. He sent Lady Violet V. I. Okoye for leadership training at Columbia University, New York, and appointed her as the first long-time Organiser of the C.W.O., supported by Sister-Advisers Sr. Mary Magdalene Brady (MSHR) and Sr. Mary Consolata Anyacho (IHM). Under their leadership, the C.W.O. spread rapidly across Nigeria.