Module 3:
The Trinity: Father, Son, and Holy Spirit

Module 3 explains the doctrine of the Trinity as the mainstream Christian attempt to hold together three claims at once: there is one God, Jesus is treated in divine ways, and the Holy Spirit is understood as divine and active. It traces how this doctrine developed historically through early Christian debates and church councils, then explains the core Trinitarian claim that God is one in essence and three in persons: Father, Son, and Holy Spirit.

The module presents the main biblical, historical, logical, relational, and salvation-based arguments that Trinitarians use to defend this doctrine. The module then presents major arguments against the Trinity, especially from strict monotheism, Jesus’ relationship to the Father in Scripture, the Jewish understanding of the Holy Spirit, logical concerns, and the doctrine’s historical development. It shows that not all Christians accept Nicene Trinitarianism and outlines several alternative views, including Jesus as God’s uniquely Spirit-filled Messiah, Jesus as the one God revealed in flesh, and more symbolic understandings of God, Jesus, and the Spirit. Overall, the module presents the Trinity as one of Christianity’s most important and most debated teachings because it touches the deepest questions about the identity of God, Jesus, the Holy Spirit, and the meaning of monotheism.