Galatians 2:20 I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me.
21 I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.
This tells exactly what happens to the believer in Christ. When we turn ourselves over to God we are in a sense crucified with Christ. We die to the fleshly desires of the body and Christ takes up residence where theses desires lived. We turn our will over to God. It is our faith in God which gives us the confidence to turn ourselves over to the will of God. Temptations fade away, because we turn the decision making over to Him. Christ in us, the hope of glory. The last verse tells us that those who insist they can earn salvation by their own efforts undermine the foundation of Christianity and render unnecessary the death of Christ. If we could have been saved by the law, then it would have been useless for Jesus to give His body on the cross for us. But the law was there to show us just how much we needed a savior Christ died on the cross and shed His blood for our salvation so we can spend eternity with Him.