I have a question thats really been bothering about religion christ..?

Okay i understand the ONLY way to get into heaven is to accept that christ died for your sins..but how about muslim people do they go to heaven? they belive in the same god.. but they just dont bleieve it was actually jesus that died on the cross it was someone that looked like him.. thats what it says in the quran and the quran to muslims is just like the bible to christians.. how can we know which one is right which one is accurate? say christianity was the right religion it was jesus that died on the cross will god still send muslims to hell? i mean its not really their fault they were brought up in that relgion and they truly belived that their teaching was the way to god and they loved god in their hearts..its not really their fault im sure god knows thats and he is fair with them...i mean say just say mohammed the prophet was wrong,... but i mean we are generations down frrom that.