Melchizedek - priest of God

The epistle to the Hebrews is yet another illustration of how the Old Testament revelation anticipated the coming Messiah.
Paul enters into great detail to show that the Levitical sacrificial priesthood foreshadowed the priestly office and work of Christ. Yet at the same time, the Old Testament revealed that Messiah would not come from the tribe of Levi, or the family of Aaron as was requirred in the law. The appearance of Melchizedek indicated another order, which typified the priesthood of Christ.