This is SDA Holy Spirit Debate Now vs Then part 3! The main point this time is that throughout Christian history, there are been non-trinitarian theologies that affirm the personhood of the Holy Spirit. This makes it clear that the question of whether or not the Holy Spirit is a person is distinct from the question of whether trinitarianism is true. Modern SDAs tend to not be familiar with this historical reality and thus assume that anyone who accepts the personhood of the Holy Spirit is probably a trinitarian while anti-trinitarians are assumed to deny the personhood of the Holy Spirit. Early SDAs understood the distinction between these questions and we need to understand it as well in order to rightly comprehend early-SDA ideas regarding the personhood of the Holy Spirit.

Blog Article: Non-Trinitarians Who Say the Holy Spirit Is A Person - (bdsda.com)

Modalism: Modalistic Monarchianism - Wikipedia

Sabellianism: Sabellianism - Wikipedia

Patripassianism: Patripassianism - Wikipedia

Tritheism: Tritheism - Wikipedia

Arianism: Arianism - Wikipedia

Holy-Spirit-is-an-angel-ism: Pneumatomachi - Wikipedia

Holy Spirit as Angel in Islam: Rūḥ - Wikipedia

R. A. Underwood's The Holy Spirit A Person (with my introduction): The Holy Spirit A Person by R. A. Underwood - (bdsda.com)