I would agree if it was some random dude but the fact that actually a great Nation came out of him and then even all nations where blessed in him and now worship the God of Abraham is strong evidence that he was right all along.
And yet, no one would have ever thought that the God of this small country, Israel, who did not intend o spread their religion, would be worshipped by people of all the world but yet it was prophesied and yet it happened.
Isreal isn't a country. Also, if you look at history it's pretty common that some random person and some random text can start religions. It just takes people wanting to believe and be a part of something that other people around them are a part of. There is nothing special about any one religion.