Be justified by faith in Christ and not by observing the law

Galatians 2:15-21
We have to put out faith in Christ Jesus that we may be justified by faith in Christ and not by observing the law, because by observing the law no one will be justified.(因信稱義。)
I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me.
Why?
Having once gained freedom through faith in Christ, how could they rebuild the system of law they had torn down? The Christian life is to be lived just as it began - by faith.
The real sin lies not in breaking Jewish food laws, but in turning back to the system of law.
We are justified by faith in Christ and not by observing the law, it is the foundation of our faith and to be a Christian. So as to all gentile that my be called Christian.
How?
Be justified by faith in Christ and not by observing the law.