Newton was in fact an Arian. He denied the divinity of Christ.
Please HayekRocks: Give me a source for that?
Arius did not deny the divinity of Christ so why would one of his followers? The answer of course is that Newton didn't deny the divinity of Christ while he certainly questioned Trinitarian doctrine at certain points of his life. But there were many Christians extant before Trinitarian doctrine ever existed. IOW's the two are not mututally exclusive, that being a belief in the divinity of Jesus of Nazareth and being agnostic on the trinity are not two inputs to an exor gate.