These folk are called "Jesus-Only Pentecostals". They are correct about the doctrine of the Trinity being of pagan origin. However, their doctrine that Jesus is God makes no sense at all and is really just a variation on the theme of the Trinity.
Jesus was a man and is a man otherwise his sacrifice and his tempations were a sham. How could God ever really be tempted? Yet we are told that he was tempted in every way as we are yet without sin. Their doctrine makes that passage into a lie. Even now, as our glorified mediator, Jesus is called "the man Christ Jesus". (1 Timothy 2:5)
If Jesus is really God come down to earth as a man, think of the absurdity of him praying all night as he often did. Was he talking to himself? Here's a case in point:
Hebrews 5:7 Who in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears unto him that was able to save him from death, and was heard in that he feared;
If Jesus is God in human form then no one was home in heaven! To whom did Jesus offer up his prayers and supplications? Who was it that "heard" him? As C.S. Lewis said in his book, "The Problem of Pain","Nonsense does not cease to be nonsense just because we speak it about God."
Here is a link to information you might find helpful:
Jesus: God the Son or Son of God? (Please click on the title.)
I hope you have found this helpful.