What does the Bible say about the mediator of the New Testament?

In Hebrews 9:15-17, it is clearly stated that Christ serves as the mediator of the New Testament. His role as mediator is critical because it signifies that through His death, the promises of the New Covenant are made available to all those whom God has chosen to receive the inheritance of eternal life. The execution of God's covenant depends upon the sacrificial atonement made by Christ, which fulfilled the requirements of justice and established a better promise than the previous covenants.