Language originated as a system to facilitate communication. As of early 2007, there are
6,912 known living human languages, according to "Ethnologue: Languages of the World, Fifteenth edition" (courtesy: Wikipedia). A "living language" is simply one which is in wide use by a specific group of living people. The exact number of known living languages will vary from 5,000 to 10,000, depending on the precision of one's definition of "language", and in particular according to how one treats dialects. There are also many dead or extinct languages.
Trouble starts when the passion or excessive love for one's own language leads to linguistic chauvinism. The word does not require a judgment that the chauvinist is right or wrong in his opinion, only that he is blind and unreasoning in coming to it, ignoring any facts which might temper his fervor. In modern use, however, it is often used pejoratively to imply that the chauvinist is both unreasoning and wrong.
Human beings should put an end to developing hatred among speakers of different languages as it serves no purpose other than dividing society based on another pretext.