I would direct you to Romans 8:
Rom 8:1¶[There is] therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
2For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
3For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
4That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
5For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
6For to be carnally minded [is] death; but to be spiritually minded [is] life and peace.
7Because the carnal mind [is] enmity against God: for it is not subject to the law of God, neither indeed can be.
8So then they that are in the flesh cannot please God.
9But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his
10And if Christ [be] in you, the body [is] dead because of sin; but the Spirit [is] life because of righteousness.
11But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
In the Mishnah, the commentaries on the law of Moses, there are some twenty-three chapters devoted to the interpreting of the law of the Sabbath day. Makes you understand why we need Jesus.