Answers (3)
If youIf you are talking about to read messages from a friend's account then it is not possible to access anyone's account and read their messages but if you are talking about to read messages which are sent by your friends for you then go into your Facebook account and in the left hand side, you will see the option messages hence from that you can able to read messages which are sent by your friends.
if what you wanted to do is read the messages from their account i dont think its possible unless, you know how to open or log in in their account or it can also be possible if you can hack it. But if you cant do any of those i dont think its possible.On the other hand if your talking about reading their messages for you you just go click your name that will direct you to your profile or wall go to the messages and there you can see their messages for you