Why is the change from the Levitical law to the new law important for Christians?

In Hebrews 7:12, it is articulated that with the change in the priesthood comes a change in the law. The Levitical law could not provide perfection or righteousness, as clearly outlined in Hebrews 7:19. The new law, established through Jesus's sacrifice, emphasizes grace and the fact that believers are made righteous by faith in Him rather than through works. This foundational shift is crucial as it underscores that our standing before God is based on Christ's completed work, providing the assurance of salvation and effective intercession.