Colossians 2:14 Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross;
The law that was against us. By the law we were condemned. That condemnation that was placed upon the seed of Adam, the entirety of the human race, was left at the cross for us. Paul describes this as if it was nailed to the cross with Him. Christ bore the sins of His people.
Psalms 103:12 As far as the east is from the west, so far hath he removed our transgressions from us.
The sin that was against us is now gone. The sin was taken away by the propitiation, the mercyseat, the sacrifice of Christ. Chapter 3 then concludes with these words.
Romans 3:28 Therefore we conclude that a man is justified by faith without the deeds of the law. 29 Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also: 30 Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith. 31 Do we then make void the law through faith? God forbid: yea, we establish the law.
The contrast between the law of works and the law of faith is seen in verse 28. You cannot forget what Paul has established to this point. Righteousness has come to us by this law of faith; by the faith of Christ. Paul goes on to show that not only was this law of faith for Jews but also for Gentiles. It is for whom John would descirbe in 1 John 2 as the whole world.
1 John 2:2 And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.
This propitiation was not just for Jews but also Gentiles. It was for the whole world; the world being comprised of both Jews and Gentiles. What Christ did was to fulfill the law in all of its requirements down to the last jot and tittle.
Matthew 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
What Christ did for us was to fulfill the law in our place. He had turned what was against us and made it for us. When He said it is finished it was as if we had followed the law perfectly. If He represented us, as we had once been represented by Adam, then by His obedience we receive all the rewards that would be given for doing just that. Christ was representing us. Whatever He earned in doing so, we get. He earned righteousness, we get righteousness. It was the same for the circumcision and for the uncircumcision. Both Jews and Gentiles are made righteous in the same way and at the same time. It was by the propitiatory act of God whereby He made sinners just in His sight by the imputation of the righteousness earned by Christ through His obedience unto death. We are justified by faith, the faith. In doing this, the law is not taken away, it no longer condemns us. On the contrary, the law now is for us, it is established. It is as if we fulfilled all the law and now, we stand in the sight of God as righteous/justified.