The Trinity in Christianity is a difficult structure to grasp. The nature of the son Jesus Christ and the Holy Spirit and their relationship with the Father are among the most debated topics in religion. This book delves into the concept of the Holy Spirit and investigates the process of it becoming a dogma in Christianity. The author starts by exploring the idea of spirit in Judaism to contextualize what came after. The author also studies the debates about the Holy Spirit and how the religious thinkers understood and used the idea in early Christian texts.