Human beings, because of sin, are cut off from God and unable to bring themselves back to God (Genesis 3:22-24; Isaiah 59:2; Ephesians 2:3; Colossians 1:21; see SIN). Therefore, there needs to be a mediator who can stand between them and God, and somehow bring them back to him. The only person who can really do this is Jesus Christ. He alone was both human and divine, and, being sinless, bore sin’s penalty on behalf of the guilty. Through him repentant sinners can be brought back to God and enjoy the fellowship with God that he desires for them (2 Timothy 2:5-6; 1 Peter 3:18; see RECONCILIATION; REDEMPTION).
The work of Jesus through his life, death and resurrection is therefore the basis on which God deals with human sin and brings repentant sinners back to himself. This applies even to believers who lived in Old Testament times. Such people may not have known about Jesus’ death, but the eternal God did (Revelation 13:8).
Through the nation Israel God taught the principles of his salvation. He chose Israel to be his people and gave them an order of priests and sacrifices as a means of approaching him (Exodus 19:5-6; Leviticus 4:27-30; Numbers 3:10; see COVENANT; PRIEST; SACRIFICE). In making the covenant with Israel, God used Moses as the mediator (Exodus 24:3-8; Acts 7:38; Galatians 3:19-20). The people, in their approach to God, used the priests as mediators (Leviticus 5:17-18; Leviticus 16:15-17; Hebrews 5:1).
With the coming of Jesus Christ, the covenant with Israel had fulfilled its purpose. God has now established a new and eternal covenant, Jesus Christ being the mediator (Hebrews 8:6; Hebrews 9:15; Hebrews 12:24). He is also the priest through whom people approach God (John 14:7; Hebrews 4:14-16; Hebrews 9:24; Hebrews 13:15; 1 Peter 2:5). The basis on which this new covenant operates is Christ’s sacrificial death (Colossians 1:21-22; 1 Timothy 2:5-6; Hebrews 9:11-15).
Yet the earthly life of Christ is also important. Because of his experiences as one who has lived in the world of ordinary people, he understands the problems of believers. As a result he can plead sympathetically with God on their behalf, as well as bring God’s help to them (Hebrews 2:17-18; Hebrews 4:15; Hebrews 7:25). (For further details see PRIEST, sub-heading ‘The high priesthood of Jesus’.)