But PS, wasn't the Old Law and OT given from god himself? Why would something god devised be in need of redemption?
Any Law God gave to Man was filterd THROUGH Man, and man is fallen and in need of redemption.
Jeremiah warns about the alterating of the Law by the scribes in Jeremiah 8 and even Ezekiel comments that because of How the Hebrews were, "God" gave them "laws" that were not good as punishment.
It seems that with all of creation being in need of redemption, the bible would fall into that category too and redemption came in Christ and His teachings.
Is it useless? No. Is it perfect, the bible itself gives warning that only God is perfect.
The purpose of the bible is to point to the fact that Man is in need of redemption and the bible makes that clear as we read the Good, the bad and the ugly of it.
It does however POINT the way to redemption In Christ and in that it is just like creation, not perfect but perhaps "good enough" ?