If popularity is the contingency for deciding Truth, then if China is anything to go by, Communism is the greatest political system ever invented.
I'll try to keep this on religion, rather than politics, though. My main concern is that it is so easy for the individual to think that they know "Truth" - and I know there are a lot of people who are present, or who have passed through this forum, and believe to some degree that they have known Truth, either as a strictly personal experience, or as part of embracing an existing religion as offering a sole Absolute. I don;t exclude myself from this list, either, which is all the more reason why I consider the acceptance of the relative position of religious thought as ultimately of most concern - ie, it is not what we think as most important, but how we behave. In which case, the relative differences become far less of an issue, IMO, if that action is perceived generally to be good - ie, compassionate action.