“Nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, so that we may be justified by faith in Christ and not by the works of the Law; since by the works of the Law no flesh will be justified. (Galatians 2:16 NASB)
Paul is putting the gospel in a nutshell. Knowing here [oida] having a fullness of knowledge or complete knowledge. “Yet ye have not known [ginōskō] him; but I know [oida] him: and if I should say, I know [oida] him not, I shall be a liar like unto you: but I know [oida] him, and keep his saying. (John 8:55) God showed Paul this very important doctrine. Now Paul has a complete knowledge and perception of these doctrines.
We are not justified or made righteous by the law. “Yet we know that a person is made right with God by faith in Jesus Christ, not by obeying the law. And we have believed in Christ Jesus, so that we might be made right with God because of our faith in Christ, not because we have obeyed the law. For no one will ever be made right with God by obeying the law.” (Galatians 2:16 NLT)
Our salvation has nothing to do with keeping the law. It has nothing to do with the law. We can’t be made righteous by obeying the law not for salvation and not after salvation. We are in Christ by faith. By believing, alone we are made righteous and in right standing with God. It’s not by any works we can do. The whole plan is through Jesus alone and we are placed in Christ by grace through our faith.
No flesh, not man, woman, or child can make himself righteous by anything he might do. He can’t buy his way in. He can’t obey his way in. He can do nothing apart from believing in the finished work of Jesus on the Cross. Anything a person might add to that is in error. We can’t be good enough. We can’t work our way in. It is solely by unmerited favor. It is a gift we receive by faith.
You are in Christ by faith. It is a done deal. Now live in the grace you have so graciously received.