Do we understand what we teach?

From Galations 2:11 - 18
" When Peter came to Antioch, I opposed him to his face, because he was clearly in the wrong. Before certain men came from James, he used to eat with the Gentiles. But when they arrived, he began to draw back and separate himself from the Gentiles because he was afraid of those who belonged to the circumcision group. The other Jews joined him in his hypocrisy, so that by their hypocrisy even Barnabas was lead astray.
When I saw that they were not acting in line with the truth of the gosple, I said to Peter in front of them all, "You are a Jew, yet you live like a Gentile and not like a Jew. How is it, then, that you force Gentiles to follow Jewish customs?
We who are Jews by birth and not 'Gentile sinners' know that a man is not justified by observing 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 observing the law, because by observing the law no one will be justified.
If, while we seek to be justified in Christ, it becomes evident that we our selves are sinners, does that mean tht Christ promotes sin? Absolutely not! If I rebuild what i destroyed, I prove that I am a lawbreaker."
I continue to be surprised at the ignorance of men in their understanding of scripture. Just as Peter, a leader of the church in Antioch came to Grace, then reverted to entertaining those Jews who continued in the law of Moses, men of today, who claim to have stood in the pulpit still have no understanding of what saves them.
Once you've explained what righteousness is, then have presented this passage to a person with the word 'justified' (dikiasune in Greek: to make or render right or just; to act with justice; to avouch to be good and true, to vindicate; to hold as guiltless, to accept as righteous, to justify") a person will still continue to treat salvation as if it is an automatic entrance to Heaven.
Any of the descriptive words in the salvation process may be wrongly misused. Words like: righteous, perfect, sanctified, justified, consecrated and holy will all have the same meaning to someone who does not understand what these words are intended to describe.
The word 'justified' is like a qualification. To be justified is to be seen by God as someone whom He can have a relationship with. Justification comes by atonement.
Atonement is to meet the requirements of God's law. Then we are called righteous or justified.
Christ becomes our perfect living sacrifice in which he fulfilled the demands of the law. Now, His human blood atones for us because He offers Himself as a sacrafice for us. We are seen as one who has fulfilled the requirements of the law when we accept His work as having been done on our behalf.
This is faith; that we believe in Him just as Abraham believed in Him.