Pius IV confirmed the Council`s decrees in 1564 and published a summary of his statements in teaching; Compliance with disciplinary decrees has been sanctioned. In a short time, the Catechism of Trent was published, the Missal and Breviary were revised and a revised version of the Bible was finally published. By the end of the century, many of the abuses that had motivated the Protestant Reformation had disappeared, and the Roman Catholic Church had taken over many of its supporters in Europe. However, the Council failed to heal the schism that the Western Christian Church had destroyed. Another priority of the counter-reformation was a continuous missionary project in some parts of the world, colonized by Roman Catholic countries such as Spain and Portugal. The work of men like St Francis Xavier and others in Asia and missionaries in the New World has been rewarded with millions of baptisms and even authentic conversions. There have also been attempts to transform areas of the world that were Roman Catholics, such as .B England and Sweden. Most of the „German states” in which Luther worked remained Protestants after his death in 1546, but large areas, mainly Bavaria and Austria, were reclaimed for Catholicism at the end of the 16th century. The wars of religion between 1562 and 1598 returned to France for the Roman Catholic cause, although the edict of Nantes (1598) granted limited tolerance to Protestants; it was revoked in 1685. Perhaps the most complete victory for the counter-reformation was the restoration of Roman Catholic rule in Hussite Poland and Bohemia.

Several theologians – in particular the Jesuit St. Robert Bellarmine – attacked the doctrinal positions of Protestant reformers, but there was no one to compete with the theological and moral commitment that could be seen in Luther`s writings or in the eloquence and passion that characterize John Calvin`s works. Catholics tended to emphasize the beliefs and subjects of devotion that were directly attacked by Protestants-z.B the actual presence of Christ in the Eucharist, the Virgin Mary and St. Peter. The Librorum Prohibitorum Index was created in 1559 to combat the dissemination of certain writings of the Protestant Reformation. At the time of the opening of the Council, some bishops insisted on immediate reform, others for clarification of Catholic teachings; A compromise was reached to address both issues at the same time. The Council then laid the groundwork for future declarations: the Niceno-Constantinopolitan Creed was accepted as the foundation of the Catholic faith; the canon of the books of the Old and New Testaments was definitively established; Tradition has been accepted as a source of faith; Latin vulgate was declared sufficient for teaching; The number of sacraments has been set at seven; and the nature and consequences of original sin have been defined. After months of intense debate, the Council has decided against Luther`s doctrine of justification by faith alone: man, according to the Council, is justified internally by collaborating with the divine grace that God gives for free. By imposing on bishops the obligation to reside in their respective places, the Church has effectively abolished the plurality of dioceses. Political problems forced the Council`s move to Bologna and eventually completely halted its unfinished work.

Before the military events imposed a second postponement of the Council, the delegates concluded an important decree on the Eucharist that defined the actual presence of Christ as opposed to the interpretation of Huldrych Zwingli, head of the Swiss reform, and the doctrine of transubstantiation, contrary to that of Luther`s consubstantiation.