What is the duty of the trial court to instruct the jury on the principles of law relevant to the issues raised by the jury in a criminal case?

"The general rule is that in a criminal case the trial court must instruct on the 'principles of law relevant to the issues raised by the evidence [citations] and has the correlative duty "to refrain from instructing on principles of law which not only are irrelevant to the issues raised by the evidence but also have the effect of confusing the jury or relieving it from making findings on relevant issues." [Citation.]' [Citation.]" (People v. Barker (2001) 91 Cal.App.4th 1166, 1172.)