How can I forgive him?

my friend bob has this bro john he says harrases ppl and all this stuff that will just kill ur inside. another friend of mine shelly, well john IMs her all the time and flirts with her and evrything. he really is a nice guy when he wants to be. personally i think bob just has issues with his bro. he used to call his bro the best bro in the world until john was in 6th grade (hes in college now). u know when boys try to change their good boy status, i guess something went wrong with the brothers at that time. well lately john wanted my sn badly, he even beat up bob for it but bob refused to give it to him. bob gave me his bro's sn and told me to block him if he ever trys to IM me, today he pretended to be his bro and IMed me. I was scared and then he kept saying harsh things. i was about to cry cuz i didnt want to hurt bob my talking to his bro and i was afraid of saying the wrong thing. john will beat him up for the littliest thing. he told me it was him later. its the cruelest thing.p2