‘The light that should illuminate our school is the light that Jesus brought to earth’. We know that it is the school's duty to provide students with an excellent education, preparing them not only for life, but first and foremost for heaven. The Catholic teacher, who has the task of teaching children to read and write from an early age, has the duty and mission of teaching them both religious and secular science, which must always be centred on the truth of the faith. Although secular science is part of the school curriculum, the Catholic teacher must know what to teach and how to teach it. We must always bear in mind what our Divine Master taught us. To this end, teachers need to be constantly trained. It is up to the teacher to prepare the lessons, the teaching material to be used and also to critically analyse the textbooks and workbooks that will be used in literacy. Therefore, the Catholic teacher must be well prepared from their initial training , bearing in mind that the ‘Gospel’, being our Catholic pedagogy, ‘sets limits that free human reason, because they prevent it from making mistakes, and prevent it from going astray’.