"On Baptism" (De Baptismo) is a philosophical and theological treatise by the famous Roman writer Tertullian, which was written in the III century. In this work, Tertullian argues his opinion about the role and significance of baptism in Christian life. The author highlights the ritual of baptism as a way of cleansing from sins and entering a new spiritual life in Christ. The book "On Baptism" (De Baptismo) reveals the deep meaning of the church rite of baptism and contributes to a better understanding of its meaning for believers. With his wise approach to this topic, Tertullian leaves a mark in the hearts of readers and inspires reflection on the sanctity and importance of baptism in the spirit of Christianity.