Bible Verses About Priests: Services of, ineffectual for removing sin

Now if there was perfection through the Levitical priesthood (for under it hath the people received the law), what further need was there that another priest should arise after the order of Melchizedek, and not be reckoned after the order of Aaron?

And every priest indeed standeth day by day ministering and offering oftentimes the same sacrifices, the which can never take away sins: