If we as humans are not tolerant, we will lose our minds. It would drive the people around us crazy and we would lose friends and family. Burning bridges you could say.
Society will fall to a ruin, the world will be in turmoil. Not only that, but we will be fighting amongst ourselves instead of standing as a united front.
Basically, if we aren't tolerant and respectful, the world as we know it will come crashing down.