The argument from the lesser to the greater, which has been going on since the first page of Hebrews, continues here. The earthly place of worship and form of worship is only a dim reflection of heavenly things.
The blood of bulls and goats is only a temporary solution to sin. Ho much more will the blood of Christ cleans our consciences from dead works to serve the living God. The blood of Jesus offered once and for all forgives sin (the problem) and cleanses our consciences (the reminder of the problem).
Jesus offering himself once and for all was more than enough to forgive sin.