I think, if you want to get to the root of the problem, you have to address the Catholicity of the school. The school motto is only meaningful if viewed through a Catholic lens. The religious/spiritual culture of the school needs to be developed, focussing on the faith formation of administration, faculty and staff. To that end, a five year program of reading, discussing and integrating faith and education would go a long way. This is all contained in the Vatican document, Lay Catholics in Schools: Witness to Faith.