Oi vey! Jesus already came to be the sacrificial lamb. Let's not go back to the failed covenant for salvation. We're the ones who failed it!
The Apostle Paul makes it very clear in Romans 8:10 that the physical body, mind / intellect, and the heart (which is evil - Jeremiah 17:9) has been rendered helpless because of the original sin; consequently, the Believer trying to overcome by willpower presents a fruitless task. Only the Holy Spirit can mortify the deeds of the flesh and make us what we ought to be (Romans 8:13). This means we cannot do it ourselves. Once again, He performs all that He does within the confines of the Finished Work of Christ (Romans 8:2).
If a Christian will and their efforts to live for God is in anything except Christ and the Cross, i.e., Finished Work, The Blood of Jesus (Romans 8:2), Satan can override your will and force you to do things you don't want to do and trying not to do (Ephesians 6:12). Jesus said deny yourself and pick up your cross and follow me (Luke 9:23).
Remember our bodies are dead and useless to God. The heart is prone to wander away from God's love and eat from "The Tree of Knowledge of Good and Evil." The reason why the body is dead is because of the effects of the fall has made us totally incapable of yielding spiritual obedience on a regular basis (Jeremiah 13:23). So there must be a source outside of myself that helps me to enter into sanctification which is the Holy Spirit (Romans 8:13).
The truth is the entirety of the system of this world is evil. Paul said:
"Who gave Himself for our sins, that He might deliver us from this present evil world, according to the Will of God and our Father" (Galatians 1:4).
There is only one solution, as it regards this foe, and that is "Jesus Christ and Him Crucified," and our Faith in that Finished Work.