Why does every religion believe only they will go to heaven while all others wont?

Why do these Christians keep believing that the only way to get to heaven is through Jesus? Thats just one particular fictional character for that religion. Every other religion has some other idea that they will go to heaven and everyone else who doesnt follow them will go to hell. What makes every religion believe only theirs is right while all others are wrong? Its just a mere accident at birth that you were this religion. Which belief could be right and which is wrong? I dont get how people could continue to believe in this while all the other religions are against them.

Most people like to hear that they are right, and they like to see themselves as superior. This is unfortunately one of the traits left over from the caveman days, a type of survival. Therefore, I believe that regarding religion, people like to see themselves as right in their beliefs, but since most religions have the same basic principles, there is no wrong one. Each person must just make that decision themselves as to what they want to believe, in a more powerful being, or not. As to the Heaven vs. Hell thing, it is considered to be the ultimate paradise to go to heaven, whereas Hell is the punishment. People just like to see other suffer while they triumph. We’re a cruel species.