How do we know the new priesthood is better than the old one?

The superiority of Christ's priesthood comes from God's own declaration, stating, 'Thou art a priest forever after the order of Melchizedek' (Hebrews 7:17). This priesthood does not rely on genealogical lineage as the Levitical priesthood did, instead, it operates by the power of an endless life. In Hebrews 7:12, the writer emphasizes the necessity of a change in the priesthood, which correlates with the new law established through Christ. While the old covenant was temporary and ultimately unprofitable for salvation, the new covenant affirms the eternal work of Christ, providing a sure hope and assurance for believers.