Why the Old Testament is inferior to the New.

"The specifically Jewish national morality and national religion of the Old Testament have been superseded. The Old Testament remains important because it records the history and decline of a people that repeatedly separated itself from God despite His revelation. The prophets of God show us all that the position of a nation relative to God is decisive for its fate in history. [...] However, we also see in the Old Testament the initial glimmers of God’s love which is fully revealed in Jesus Christ. Because of this understanding, [we] cannot abandon the Old Testament."

Though this teaching may come as a surprise to many modern Christians, this is what the historic Christian Church has taught. In the words of St. Augustine, “The New is hidden in the Old, and the Old is made clear in the New”. The Old Testament exists in preparation for the New Testament, and thus we can still find Christ within the pages of the Old Testament, but only when we read it through the lense of the New.

The Old Testament was written at a time in which humanity had no possibility for redemption, and thus cannot provide us with the salvific grace of Jesus Christ. In Lutheran terminology, the Old Testament reveals the Law, that is, the Mosaic Law. The Mosaic Law has three distinctions: the Civil Law, how ancient Israel should be governed; the Ceremonial Law, the ceremonies (ritual purity, temple worship, sacrificial atonement) the Jews ought to practice; and the Moral Law, the eternal, unchanging commandments God requires all of humanity to follow.

Two of these Laws (Ceremonial and Civil) were fulfilled by the coming of the Messiah (though not in the same way. The Civil Law may still be applied to modern nations, despite being unnecessary, but the Ceremonial Law should never be practiced by Christians under any circumstances, and is a direct insult to Christ’s sacrifice to do so), the only remaining Law is the Moral Law. However, through both the teachings of the Old and New Testaments, it becomes clear that we cannot satisfy God’s moral demands on our own. This is where the Gospel comes in. The Gospel is Jesus fulfilling the Moral Law for us, requiring only that we have faith in Him to achieve salvation.

Jesus says in Matthew 13, “Blessed are your eyes, for they see: and your ears, for they hear. For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them.”

Similarly, the Old Testament, as previously discussed, reflects the Jewish folk religion that in many respects cannot and should not be applied to the Gentiles. Things such as circumcision, dietary restrictions, ritual purity, Temple worship, Levitical priesthood, sacrifices, tribal inheritance, genealogical qualifications, and the separation of Israel from the Gentile nations are all religious expressions unique to the Jewish people. 

As it is the case that much of the Old Testament is dedicated to the the Jewish Ceremonial and Civil law now fulfilled by Christ, and the then unfulfilled Moral Law, much of the Old Testament is rendered obsolete through Jesus.