Q: How did Christ fulfill his priesthood?

Ecclesiastes 12: 13 I have heard all these things, to the effect that it is human duty to fear God and keep his commandments. Let me add here that since keeping the commandments is a duty and an obligation, there is nothing to boast about. Therefore, we are not saved by obligation, that is, we are not saved by good deeds. We are justified by the blood of Jesus Christ.