As for as being open minded towards other religion concern there is no issue itself but if one has not strengthened his own faith in Islam then most probably he would be misguided( it doesn’t mean that one should be narrow minded). First we should have clear proof and learn philosophy of our own religion then he can do research or comparative studies because many times we have observed that there are many scholars who born in Muslim family but unfortunately have no knowledge of Islam and have university degree in western philosophy or Buddhism philosophy or Hindu Philosophy and the other side they didn’t have any knowledge in Islamic philosophy. Rather they have practically seen the behavior of ISIS like people and their ideology then reached to this conclusion that Islam has said nothing about spirituality and humanity and human rights but other religion are very peaceful and work in humanitarian cause. While if we study Islamic spirituality and rights we will find that none of the religion have such treasure of knowledge as Islam has.
So be free and learn what others say but same time build your own faith stronger in Islam.