15 “We who are Jews by birth and not sinful Gentiles 16 know that a person is not justified by the works of the law, but by faith in Jesus Christ. So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not by the works of the law, because by the works of the law no one will be justified. (Galatians 2:15-16)
In today's text, the Apostle Paul clearly states "a person is not justified by the works of the law, but by faith in Jesus Christ." At this point in the letter Paul interjects for the first time a very important word, the word “justified.” Justification is what a judge does in a court room. It is when the judge declares that a defendant is found innocent and just.
We were all born sinful and we have all sinned. We are guilty as charged. We deserve the full sentence of condemnation. Obeying the law cannot save us. We have broken God’s law. Now, the law condemns us.
The real question is: how can we be make right before God or justified before God? How can God, the judge, declare us righteous and innocent? The answer is that Jesus Christ lived and died to provide our righteousness and bear our punishment. It is by trusting Christ that His righteousness is imputed to us and his death is counted as ours.
Faith alone unites us to Christ. Not works. No amount of human goodness can connect us with Christ. Only His righteousness and atonement makes us acceptable before God. For His sake alone, God counts the believer in His Son as righteous, and accepts us and welcomes us in to His family. This is the heart of the gospel—the good news.
Justification always speaks of a transfer made that has ongoing implications. Everyone who understands they need a Savior, and they cry out to God for help and believe in the finished work of Jesus Christ on the cross, it is then that they experience justification.

It is in our spirit that we directly experience the result of having been made "just" in God's eyes. And, as a result, we are made alive to God spiritually.