This thesis examines the sacrament of baptism in the teachings of different Christian denominations. It focuses on the Reformed, Roman Catholic, Orthodox, Baptist, Seventh-day Adventist, Pentecostal, and Unitarian churches. The aim of the study is to explore the theological foundations of baptism and to compare these teachings with the doctrine of the Reformed Church. The research is based on confessional writings, theological works, and official church documents. A separate section discusses the biblical basis of infant baptism and believer's baptism. The study shows that almost all denominations teach that baptism was instituted by Christ. However, there are important differences in the understanding of baptism as a sacrament, the role of grace, and the practice of infant or adult baptism. The findings suggest that while many churches share similar biblical foundations, their interpretations differ. The results may contribute to better understanding between denominations and support ecumenical dialogue.