Our Lord Jesus Christ came here as a Man, as our Mediator, Substitute and Representative to do and fulfill the will of God, to bring in a better covenant. Verses 5-8 are a quotation from Psalm 40:6-8 in which David, by the Spirit of inspiration wrote of Christ who was to come.
A Body PreparedThe sacrifices and offerings of the Old Testament continued only for a set time until Christ came (1 Cor. 5:7). God never accepted them as a term of righteousness. But, when the fullness of time came, he clothed Christ in a human body prepared by the Holy Spirit, that his own dear Son might (in the body of a man) obey the law and suffer for sin (Rom. 5:19; 1 Cor. 15:21-22). God the Holy Spirit prepared a body for him (v. 5), a real human body and soul for the infinite, eternal, incomprehensible Son of God, so that he could bear our sins in his body on the cursed tree and die as our Substitute.
A Voluntary SubstituteIn verse 6 we are again told that it was impossible for animal blood to put away human sin. Burnt offerings and sacrifices could never satisfy his justice, appease his anger, honor his law, or put away sin (Isa. 1:11-18). Our Lord Jesus Christ came here as a voluntary Surety, as Jehovah's voluntary Servant, to die as our Substitute by the will of God (v. 7). In the book of God's decrees and in the Book of God's revelation (the Bible) it is clearly written that Christ would come to work out the redemptive will of God (Luke 24:44-47).
The First and the SecondIn order to fulfill and bring in the new, everlasting covenant and the blessings of it, our Savior completely took away the old (vv. 8-9). In verse 8 the prophecy of Psalm 40 is repeated. Here, however, all the sacrifices are included. That means this: – When Christ fulfilled them all he replaced them all. Those sacrifices gave no pleasure to God except as they were offered in faith toward Christ (Heb. 11:4, 17, 28).
By completely fulfilling the redemptive will of God (John 6:38), the Lord Jesus Christ has put away all sacrifices, all offerings, the priesthood and all that was associated with that covenant. "Christ is the END of the law!" He stands in the place of all that was represented in the law. Now, having Christ, we have all things in him (1 Cor. 3:21-23; 1:30; Col. 2:9,10). He who was made to be sin for us is made of God unto us Wisdom, Righteousness, Sanctification, and Redemption. Let us ever glory in him!