Abstract
The study deals with the issues of the first phase of negotiations of the Council of Trent (1545-1563), which are analysed and evaluated in a historical and theological context. It focuses on shaping the optimal relationship of the Catholic Church with the Protestant Reformation and discusses the main aspects of seeking a desirable form of the Catholic Church.
It pays attention to definitions of theological and dogmatic issues in individual steps, such as the role of the Bible and tradition, sin, justification, sacraments and indulgences. The article deals with changes in organizational and disciplinary matters, as well.