Languages and dialects

I was wondering why we have so many languages in the world. Some ancient, dead and few started recently, growing; some have written form and some dont ..

It is understandable if different languages spurn out at isolated geographical locations. However we see that many languages and dialects co-exist at a close region. One possibility could be that the people migrated and carried their language to an area where people had their own language.

There seems to be more to the story. Looks like socio-economic-political motives might have driven people to create languages. For eg, in a business environment, it is a great advantage for the salesperson to use some secret code words to discuss in front of the customer. Also, a language and a dialect could establish an identity of the customer and hence favor discounts.

Around the world, we are politically charged by emotions. We create artificial borders. These emotions are mainly based on faith or language.

In order to demark the dividing factors among human being, I would love to drop all languages and adapt a single universal language. When people start seeing language as a tool to communicate and not an emotional toy, then we may achieve this idealistic world.