Which one do you hold as correct and why?
“Because under the non-Trinitarian umbrella there can be a number of different, options: 1. Pneumatomachi: who said that the Holy Spirit is just an angel and not God 2. Arians: who said that Jesus was just an angel and not God 3. Marcionites who said the Jesus was God and the Father was not 4. denying that both Jesus and the Holy Spirit are God 5. saying that all three are modes of the other like steam-water-ice 6. incarnations/manifestations Which one do you hold as correct and why?”
I’m a 5. The word says the Word is God, and it also says Jesus is the Word made flesh. I can only see that as God was born as flesh in the person of Jesus. The word also says God is One. There are no submit gods under Him.
There was another one about the Spirit being Jesus, but I can’t remember it right now.
Sorry, but your religion doesn't get to decide which idea is Trinitarian or not Trinitarian...
Your religion has no more of the correct understanding of the Trinity than some of the others and I'd say even far less understanding...