No, he was not doing the right thing. Beware fanatics/cults of personalities who promise easy answers. The movie has its problems, but it was ahead of its time there.
Maybe Sybok genuinely thought he was helping people by taking their pain away. Even so he seemed completely unaware or unconcerned that he was leaving them so open to suggestion he was practically taking their free will away.
In the end, the point was it's better to look for god/answers within, by bettering yourself and opening yourself to the people around you, not by forcing dogma on those around you by force.