The Catholic Church has remained faithful to Sacred Scripture and Holy Tradition over the past centuries. In the 1500s, the Protestant Reformation occurred, and the Council of Trent was created in response. This council made a strong counter-reformation, which was strengthened by Pope Pius V by making the church more disciplined and uniting it by promulgating the Tridentine Mass. Then, over the course of the twentieth century, many things changed and the modern era arrived. That is where modernism comes into play.