Questions about Religions and Christianity

Why so many religions exist? Why none of them has been able to convince the world it is the right one, so that only one religion would embrace the world?

Non only, each major religion appears split into branches that are often unfriendly to each other. They all claim to possess the Truth. I find that pretty troubling.

Why the Christian revelation has not occurred in other part of the world, Africa, Asia, the Americas? Were the people who lived in the other continents less deserving of salvation?

Why the Old and the New Testament exist in languages most humans today cannot understand (Greek, Hebrew and Aramaic)? Even back then only very few could. ,The word of God can only be read in translation. Can one depend on translations for the word of God? It is a fact that people disagree on the quality of translations available. Why God, the Almighty, has not invented a language that everybody could understand, everywhere on earth? For the Almighty that would have seemed a reasonable and easy solutions.  

And what about the humans who inhabited the earth for about 300.00o years before Jesus Christ? Did they not deserve to be saved? They all died unbaptized with no chance to access Paradise. It just does not seem right.