Lima Luis Correa Historical science often presents Christianity with some uncomfortable questions. It stresses the Church's opposition to modernity, the consequences of the autonomy of science, changes in family structure and the evolution of the concept of holiness. This chapter aims to show how this is viable, with a focus on healthy relativism, the mature Christian and their potential contributions to the thought and practice of believers. The word relativism, however, inspires a great deal of fear. Cardinal Ratzinger warned against charges of fundamentalism of those who manifest a clear faith based on the creed of the Church. Another contentious point between science and the Christian faith is so-called 'natural law', a concept widely used in the moral teaching of the Catholic Church. The concept of the 'mature Christian' reflected on by Karl Rahner can be helpful and concept is somewhat different from the adult and mature faith, rooted in friendship with Christ, of which Ratzinger spoke.