I am currently studying out the book of Hebrews (I am reading the book you wrote about Hebrews along the way as well) and I’m learning a lot, but there is one question that I would like to ask. If the covenant that Moses brought was to be replaced by Jesus at some point, and God, being all knowing (God knowing the new covenant was to come), what was the point of the old covenant? I understand this covenant was to show the need for a savior and to establish what sin is (didn’t people know what sin was before the law anyways?), but if the law is impossible to follow (only Jesus did this) why would God create it as a covenant in the first place (only for it to become outdated, and unused) instead of just allowing Jesus to come and bring the new covenant (it is also superior in every way, why not just start with the better covenant), what was the point? Jesus’s sacrifice being above time, wouldn’t the sacrifice be valid for everyone in the Old Testament and everyone who lived before the sacrifice of Jesus on the cross?

Good question.  In a sense you are already answering your own question.  The Covenant at Mt. Sinai did “show our need for a savior, and to establish what sin is.”  Let me back this up with some scriptures.  Romans 5:20  “The law was brought in so that the trespass might increase.  But where sin increase, grace increased all the more.”  Romans 7:13 “Nevertheless, in order that sin might be recognized as sin, it used what is good to bring about my death, so that through the commandment sin might become utterly sinful.”  Perhaps my favorite along these lines is Gal 3:24 “So the law was our guardian (schoolmaster) until Christ came that we might be justified by faith.” We needed a guardian to prepare us for full spiritual adulthood. Because of the law, we are much more deeply aware of our sin, but also more appreciative of the grace we have in Christ.  This is a sufficient reason for the law of Moses.

But there are so many other reasons for the law of Moses.  The law was a foreshadow of the good things that were coming. Colossians 2:17 The law is a shadow of the reality that we have in Christ.  This is also found in Hebrews 8:5 and Hebrews 10:1 The law is a (fore)shadow of the things that are coming, not the realities themselves.  True, they are mere foreshadows, but they serve as physical prophecies of the good things we have in Christ.  This is stated many times and in many ways in Hebrews.  We learn about the heavenly/spiritual realities from the Law of Moses.  We learn about the sacrifice of Jesus from the Jewish sacrifices (Heb 9:14-27.  We learn about the heavenly tabernacle, from the Jewish tabernacle (Heb 9:1-13).

We learn about the priesthood of Jesus from the Aaronic and the Melchizedek priesthoods (Hebrews 2, 4, 7) We learn about Jesus himself from the life of Moses, David, Joseph and more, as they are prefigures of Christ.  In the Old Testament we have so many prophecies of Christ, which helps us to believe in Christ.  There are a seemingly infinite number of ways that the law of Moses and the history of the Jews were prophecies, prefigures and foreshadows of what we have in Christ.  All of this helps us to believe in Christ.  I wrote an entire book on this topic, which is From Shadow to Reality (available at www.ipibooks.com).

If Jesus had simply shown up at some random time and random location, then his ministry would not have born the fruit that it was able to bear because Jesus came to the Jews, who had been thoroughly prepared to receive the Savior.

John Oakes