[Northern Monkey]

What i want to know(from religious people) is why are these big three very modern monotheistic religions the true ones?
What about the many polytheistic religions which died out long before them?
If those ancient religions are not believed anymore because they died with the civilisations which created them then who's to say the modern religions which are followed today won't just die out(i'm pretty sure they will) and newer religions possibly take over?
Maybe even polytheistic ones again.They can't all be right.Are there many gods or just one?
I believe that the new religions we have today are just as relevant as the ancient ones which are no longer followed.If they were not the real ones then it is much more plausable to believe that non of them are real.They are all equal in my eyes.