Today there are about 250 languages spoken all above the world. It means, if you want to communicate every human being; you have to know 250 different languages. Dude it's crazy. it's definitely impossible.
But don't worry, I solved the problem. We, all the human beings, will come together and ignore all the languages on earth and build up a new language called worldish. All the countries will speak the same language and we won't have to learn a second language. (maybe we would need to learn allienish in the future if we will be able to connect them.)
It sounds like a good idea, but think about all the efforts governments will make to teach all citizens the 'worldish'..
besides, the language is not something you decide to make up, it's a way people developed to communicate through hundreds of centuries,..
also, what's wrong with learning a second language?
Emmm...I like the sens of creativity in your idea but, you know it's not possible, not at all, even though somehow they're try to make English kinda a worldwide language...
Just know that first of all the Arabs (and I'm one of'em) will tell you that I'm never ready to give up the language that the holly Quran is written with, and so will the Jews with their language, and you'll find half of people are too lazy to accept such a huge change so, keep your high imaginantion but let it be more realistic :p