Read Hebrews 7:11-19. Why was a new covenant needed?

 According to Hebrews, the fact that Jesus was appointed priest according to the order of Melchizedek implied that a new covenant had been inaugurated. The old covenant had been given on the basis of the Levitical priesthood (Heb. 7:11, NASB). The Levitical priests acted as mediators between God and Israel, and the law excluded anyone else from the priesthood. The author concludes, then, that a change of priesthood implies a change of the law of the priesthood, as well as the change of the covenant (Heb. 7:12, 18, 19).

 The issue with the old covenant was that it could not provide perfection (Heb. 7:11). Paul is talking about the Levitical priesthood and its ministry (sacrifices, feasts, etc.). The animal sacrifices offered through them could not provide true, total cleansing from sin, nor access to God (Heb. 10:1-4; Heb. 9:13, 14; Heb. 10:19-23).

 The fact that a new covenant was necessary does not mean that God was unfair with Israel when He gave them the old covenant. The Levitical ministry and the services of the tabernacle were designed to protect them from idolatry and also to point them to Jesus’ future ministry. Hebrews stresses that the sacrifices were “a shadow of the good things to come” (Heb. 10:1, NKJV).

 By pointing them to Jesus, the sacrifices should have helped the people put their hope and faith in “the lamb of God who takes away the sin of the world” (John 1:29, NKJV; compare with Isaiah 53). This is the same point that Paul makes when he says that the law was “our tutor to lead us to Christ, so that we may be justified by faith” (Gal. 3:24, NASB) or that “Christ is the culmination of the law so that there may be righteousness for everyone who believes” (Rom. 10:4, NIV).

 In other words, even the Ten Commandments, as good and perfect as they are, cannot provide salvation (Rom. 3:20-28, Rom. 7:12-14). They provide a perfect standard of righteousness, but they do not provide righteousness, any more than looking in a mirror can erase the wrinkles of age. For perfect righteousness, we need Jesus as our Substitute.