Galatians 5:5-6 :
For we, through the Spirit, by faith wait for the hope of righteousness. For in Christ Jesus neither circumcision amounts to anything, nor uncircumcision, but faith working through love.
God recognizes us as righteous in Jesus today, but we still wait for the final hope of righteousness to take place. It should be obvious to us that we still sin even as Christians. Our righteousness, although final in God’s eyes, has yet to be realized. That is why some of our salvation is still a hope. Until the day that we see Jesus again, we have this flesh to contend with and following the law of Moses or any other legal system for that matter, will not help us overcome this problem. Notice that Paul mentions that both Jewish law and non-Jewish effort doesn’t amount to anything in the light of what Jesus has done.
Paul tells us here that what does work is “faith working through love.” Because we still have these old sinful bodies and minds, we need some way to overcome our desire to do what is wrong. God recognizes our salvation in Christ, so should we. We need to see that our bodies are dead in Christ’s death and see that our lives are now alive in Him to do only good. That is all that is left for us to do now, but we must have faith in this fact and in all that God says about us in the Bible. It is good for us to keep our minds centered on the truth from the Bible and allow the Holy Spirit the freedom to cause us to overcome our sinful desires by the good desires that He replaces them with.
Paul goes into this subject in more detail later. Please read ahead in Galatians to learn more. You will also find more discussion in Romans.