Sport as a phenomenon of the modern age is becoming more and more widespread and thus its impact on everyday life is increasing. The availability of sports to everyone makes it universal. As sport affects the lives of an increasing number of people, so does its cultural and social impact. Major sporting events such as the Olympic Games, World and European Championships also have a significant economical impact. It is therefore not surprising that sport and its impact are at the center of research of many sciences. Also, sport is very often associated with religion. Since ancient times, sports competitions such as the Olympic Games have had a religious connection because they were held in the honor of the gods. Modern sport is a competition of athletes that focuses mainly on performance and that has no religious features at its core. Still, athletes show their religiosity in a number of ways, and prayer is one of the most common as are meditation and specific pre-competition rituals. This papre provides explanations of the concepts of faith and religion as well as ways to measure them. The connection between religion and sport nad how religion influences health-related behaviours are presented. Sport is presented from the perspective of Christianity and describes the church's teachinh on sport as well as the attitude of individual Christian authorities about it. The last part of the paper states how athletes express their own religiosity on and off the field, for what reason and for what purpose. In this paper, we will analyze the definition of faith and religiosity that will facilitate our further understanding of the connection between religion and sport and their similarities and differences. Given that Christianity and sport nurture similar Christian values such as wisdom, loyalty, courage, equality (...) it can be concluded that they represent what is at the heart of modern sport. We will also analyze Christianity and its impact on behavior and its connection to sport. Furthermore, the influence of the church on sport was contributed by Christian authorities who spoke of sport and physical exercise. Finally, we will show religiosity and the expression of religiosity in athletes.