How do we know the priesthood of Christ is eternal?

The eternal nature of Christ's priesthood is affirmed dramatically in Scripture, particularly in Hebrews 7:17, where it states, 'Thou art a priest forever after the order of Melchizedek.' Unlike the Levitical priests who served for a limited time and were succeeded by their descendants, Christ's priesthood is unchangeable and everlasting. His appointment did not depend on ancestral lineage but was established upon the oath of God, securing His eternal role as our mediator and high priest. This eternal priesthood assures believers that Christ's sacrifice and intercession on our behalf will never cease, reinforcing the permanence of our salvation. Furthermore, Christ’s high priestly work is perfected and complete, as He has already provided atonement for the sins of His people, making His priesthood effective for all eternity.