The Lord made it so simple, why does man try to mix it all up with misunderstanding the law!! God created the world and us to live within laws to make the best of life. Law was broken right away, so the first thing God did was to make a way for us to live with Him in eternity even though we are broken, God gave his Son to pay for our sins for us in eternal time. We live in human time, everything happens in sequence. God lives in eternal time, everything is now. It was through Christ that there was grace from the beginning, as we are told in the first verses of the gospel of John. When what Christ did for us happened in our kind of time, salvation was fulfilled and made perfect.
Christ overcame the power of the law to keep us from eternal life, but Christ did not cancel the law, it is part of the world. It would be like cancelling the Grand Canyon, it is not done. Paul explains the process of this cancellation. We take our sin to Christ, it cleans it out of our life. Our part in this process is to accept Christ. Christ is sin free, to accept Him as our God and leader we accept that we will to follow Him, and you can't follow Christ and follow sin. You must choose. Our flesh pulls us to sin, it is because we are human, but we are given a will that must follow Christ. It is impossible to want Christ in your life and want unkindness.