Islam, Mahabharat and Ramayana are historical incidents which most of u say as myth. They are not philosopy of Hindu religion. For philosophy of Hindus please read Vedas which will tell u what is Dharma and what is Adharma ( just or unjust) and nowhere it is said that a particular way of thinking is correct. It says " let all noble thoughts come to us from all direction". Moreover Vedas say " Ekam Sat vipra bahudha vadanti" means there is one truth which sages say in different manner. Does Quran say that other religion can also preach truth?