If a defense attorney KNOWS his client is guilty, is he morally obligated to see that justice is served?

A defense attorney's job is to just insure that the State has enough evidence to convict, that function protects all of us Most attorney's do not want to know and will not let their clients tell them if the are guilty or not. If a client admits his guilt to his attorney, it ties the attorney's hands in his defense, he can't allow the defendant to take the stand and deny or offer other false witnesses as the attorney cannot offer evidence which he knows to be false.