as the Lord directed him through Moses. This was to remind the Israelites that no one except a descendant of Aaron should come to burn incense before the Lord, or he would become like Korah and his followers.
If perfection could have been attained through the Levitical priesthood—and indeed the law given to the people established that priesthood—why was there still need for another priest to come, one in the order of Melchizedek, not in the order of Aaron?