According to pop culture accounts, the Council of Nicaea (325 AD) made up a new version of Christianity that includes the divinity of Jesus and the doctrine of the Trinity. And the Council also gave orthodox bishops absolute political power to stamp out rival, more tolerant followers of Jesus. The subtext, of course, is that orthodox Christianity is bad if not evil. And its core doctrine is false because it was the byproduct of efforts to consolidate political power and control.
According to the following video, this view of the Council of Nicaea is "a complete fairy tale" grounded in a lack of historical evidence. The video is a good antidote to some of the anti-Christian, "let's make up our own religion" hype out there, so watch it all: