Pope Paul III (1534–49) is considered the first pope of the Counter-Reformation, and he also initiated the Council of Trent (1545–63), tasked with institutional reform, addressing contentious issues such as corrupt bishops and priests, the sale of indulgences, and other financial abuses.

The council upheld the basic structure of the medieval church, its sacramental system, religious orders, and doctrine, and declined to update the ritual of the Mass since historical studies of the Mass were lacking at the time.

It rejected all compromise with Protestants, restating basic tenets of the Catholic Faith.
The council upheld salvation appropriated by grace through faith and works of that faith (not just by faith, as the Protestants insisted) because "faith without works is dead", as the Epistle of James states (2:22–26).

Transubstantiation, according to which the consecrated bread and wine are held to have been transformed really and substantially into the body, blood, soul and divinity of Christ, was also reaffirmed, as were the traditional seven sacraments of the Catholic Church.
Other practices that drew the ire of Protestant reformers, such as pilgrimages, the veneration of saints and relics, the use of venerable images and statuary, and the veneration of the Virgin Mary were strongly reaffirmed as spiritually commendable practices.

The council, in the Canon of Trent, officially accepted the Vulgate listing of the Old Testament Bible, which included the deuterocanonical works (called apocrypha by Protestants) on a par with the 39 books found in the Masoretic Text.
This reaffirmed the previous Council of Rome and Synods of Carthage (both held in the 4th century AD), which had affirmed the Deuterocanon as scripture.
The council also commissioned the Roman Catechism, which served as authoritative Church teaching until the Catechism of the Catholic Church (1992).

While the traditional fundamentals of the Church were reaffirmed, there were noticeable changes to answer complaints that the Counter-Reformers were, tacitly, willing to admit were legitimate.
Among the conditions to be corrected by Catholic reformers was the growing divide between the clerics and the laity; many members of the clergy in the rural parishes had been poorly educated.
Often, these rural priests did not know Latin and lacked opportunities for proper theological training.
Addressing the education of priests had been a fundamental focus of the humanist reformers in the past.

Parish priests were to be better educated in matters of theology and apologetics, while Papal authorities sought to educate the faithful about the meaning, nature and value of art and liturgy, particularly in monastic churches (Protestants had criticised them as "distracting").
Notebooks and handbooks became more common, describing how to be good priests and confessors.

Thus, the Council of Trent attempted to improve the discipline and administration of the Church.
The worldly excesses of the secular Renaissance Church, epitomized by the era of Alexander VI (1492–1503), intensified during the Reformation under Pope Leo X (1513–21), whose campaign to raise funds for the construction of Saint Peter's Basilica by supporting use of indulgences served as a key impetus for Martin Luther's 95 Theses.
The Catholic Church responded to these problems by a vigorous campaign of reform, inspired by earlier Catholic reform movements that predated the Council of Constance (1414–17): humanism, devotionalism, legalism and the observantine tradition.

The council, by virtue of its actions, repudiated the pluralism of the secular Renaissance that had previously plagued the Church: the organization of religious institutions was tightened, discipline was improved, and the parish was emphasized.
The appointment of bishops for political reasons was no longer tolerated.
In the past, the large landholdings forced many bishops to be "absent bishops" who at times were property managers trained in administration.
Thus, the Council of Trent combated "absenteeism", which was the practice of bishops living in Rome or
Pope Paul III (1534–49) is considered the first pope of the Counter-Reformation, and he also initiated the Council of Trent (1545–63), tasked with institutional reform, addressing contentious issues such as corrupt bishops and priests, the sale of indulgences, and other financial abuses.
The council upheld the basic structure of the medieval church, its sacramental system, religious orders, and doctrine, and declined to update the ritual of the Mass since historical studies of the Mass were lacking at the time. 
It rejected all compromise with Protestants, restating basic tenets of the Catholic Faith. The council upheld salvation appropriated by grace through faith and works of that faith (not just by faith, as the Protestants insisted) because "faith without works is dead", as the Epistle of James states (2:22–26).
Transubstantiation, according to which the consecrated bread and wine are held to have been transformed really and substantially into the body, blood, soul and divinity of Christ, was also reaffirmed, as were the traditional seven sacraments of the Catholic Church. Other practices that drew the ire of Protestant reformers, such as pilgrimages, the veneration of saints and relics, the use of venerable images and statuary, and the veneration of the Virgin Mary were strongly reaffirmed as spiritually commendable practices.
The council, in the Canon of Trent, officially accepted the Vulgate listing of the Old Testament Bible, which included the deuterocanonical works (called apocrypha by Protestants) on a par with the 39 books found in the Masoretic Text. This reaffirmed the previous Council of Rome and Synods of Carthage (both held in the 4th century AD), which had affirmed the Deuterocanon as scripture. The council also commissioned the Roman Catechism, which served as authoritative Church teaching until the Catechism of the Catholic Church (1992).
While the traditional fundamentals of the Church were reaffirmed, there were noticeable changes to answer complaints that the Counter-Reformers were, tacitly, willing to admit were legitimate. Among the conditions to be corrected by Catholic reformers was the growing divide between the clerics and the laity; many members of the clergy in the rural parishes had been poorly educated. Often, these rural priests did not know Latin and lacked opportunities for proper theological training. Addressing the education of priests had been a fundamental focus of the humanist reformers in the past.
Parish priests were to be better educated in matters of theology and apologetics, while Papal authorities sought to educate the faithful about the meaning, nature and value of art and liturgy, particularly in monastic churches (Protestants had criticised them as "distracting"). Notebooks and handbooks became more common, describing how to be good priests and confessors.
Thus, the Council of Trent attempted to improve the discipline and administration of the Church. The worldly excesses of the secular Renaissance Church, epitomized by the era of Alexander VI (1492–1503), intensified during the Reformation under Pope Leo X (1513–21), whose campaign to raise funds for the construction of Saint Peter's Basilica by supporting use of indulgences served as a key impetus for Martin Luther's 95 Theses. The Catholic Church responded to these problems by a vigorous campaign of reform, inspired by earlier Catholic reform movements that predated the Council of Constance (1414–17): humanism, devotionalism, legalism and the observantine tradition.
The council, by virtue of its actions, repudiated the pluralism of the secular Renaissance that had previously plagued the Church: the organization of religious institutions was tightened, discipline was improved, and the parish was emphasized. The appointment of bishops for political reasons was no longer tolerated. In the past, the large landholdings forced many bishops to be "absent bishops" who at times were property managers trained in administration. Thus, the Council of Trent combated "absenteeism", which was the practice of bishops living in Rome or
Counter-Reformation