Open-mindedness?

Can one sincerely believes in something, and yet at the same time be open-minded to other beliefs? Can one, for example, firmly believes that the world is round, and yet the same time, accept the fact that what others say bout the world being flat can be true? Won't that only shows how little faith he has in his beliefs, and how he can't make a stand on an issue?

Once cannot claimed to have a firm perception of the world while at the same time be open-minded that what others say can be true. Open-mindedness may very well be the primary symptom of uncertainty and doubt of one own's view of the world, and it also display publicly of one's lack of confidence of himself.

Perhaps 'tolerance' is a better word to replace 'open-mindedness', for the only way one can be open-minded is to have absolutely no or weak beliefs of his own.