The religious education and spiritual formation offered to the parents, teachers and pupils of Hilrage school is entrusted to Opus Dei, an institution of the Catholic Church founded in 1928 by St. Josemaría Escrivá. Its mission is to help people seek holiness by turning their work and daily activities into occasions for getting closer to God, for serving others, and for improving society. It is at the request of the founders that these aspects of the formation given in the school are entrusted to Opus Dei. Nevertheless, it is carried out within a framework of refined respect for all religious beliefs, since the school is open to pupils and students of backgrounds.
It is indeed noteworthy that many aspects of the philosophy of Hillrange School reflect the spirit of Opus Dei. Hard work and academic excellence become easier to pursue and achieve in the context of striving for personal holiness with a desire to please God, which is the hallmark of Opus Dei. Other areas of intersection include love for freedom, character formation which leads to the acquisition of human virtues, which forms the basis of the supernatural virtues of children of God; attention to little things in school life; upholding the dignity of everyone and respect for persons; etc. One specific way in which Opus Dei supports the education at the school is by appointing a chaplain or spiritual director to attend to the spiritual needs of parents, teachers and students. The activities of the chaplaincy include Holy Mass, confession, days of recollection and individual spiritual guidance.