Albert Barnes Commentary John 15:21

"But all these things will they do unto you for my name`s sake, because they know not him that sent me." — John 15:21 (ASV)

My name's sake. On my account. Because you are my followers and possess my spirit. (See Barnes on John 14:13.)

Because they know not Him that sent me. They will not believe that God has sent me. They do not so understand His character, His justice, or His law, as to see that it was fit that He should send His Son to die. They are so opposed to it, so filled with pride and opposition to a plan of salvation that is so humbling to men, that they are resolved not to believe it, and thus they persecute me and will persecute you also.