Galatians 2, YOU ARE DOING WRONG!

Paul Accepted by the Apostles
1 Fourteen years later I went up again to Jerusalem, this time with Barnabas. I took Titus along also. 2 I went in response to a revelation and set before them the gospel that I preach among the Gentiles. But I did this privately to those who seemed to be leaders, for fear that I was running or had run my race in vain. 3 Yet not even Titus, who was with me, was compelled to be circumcised, even though he was a Greek. 4 This matter arose because some false brothers had infiltrated our ranks to spy on the freedom we have in Christ Jesus and to make us slaves. 5 We did not give in to them for a moment, so that the truth of the gospel might remain with you.
6 As for those who seemed to be important—whatever they were makes no difference to me; God does not judge by external appearance—those men added nothing to my message. 7 On the contrary, they saw that I had been entrusted with the task of preaching the gospel to the Gentiles, just as Peter had been to the Jews. 8 For God, who was at work in the ministry of Peter as an apostle to the Jews, was also at work in my ministry as an apostle to the Gentiles. 9 James, Peter and John, those reputed to be pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the Jews. 10 All they asked was that we should continue to remember the poor, the very thing I was eager to do.
Paul Opposes Peter
11 When Peter came to Antioch, I opposed him to his face, because he was clearly in the wrong. 12 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. 13 The other Jews joined him in his hypocrisy, so that by their hypocrisy even Barnabas was led astray.
14 When I saw that they were not acting in line with the truth of the gospel, 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?
15 "We who are Jews by birth and not 'Gentile sinners' 16 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.
17 "If, while we seek to be justified in Christ, it becomes evident that we ourselves are sinners, does that mean that Christ promotes sin? Absolutely not! 18 If I rebuild what I destroyed, I prove that I am a lawbreaker. 19 For through the law I died to the law so that I might live for God. 20 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. 21 I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing!"

First of all it is obvious that our Gospel is for everyone. Here Paul is ministering to the Gentiles(non-Jews) and Peter is ministering to the Jews. In the verses following 11 Paul charges Peter with being a hyprocit. Peter was acting one way and then changed his actions(follow Jewish customes) when around other Jewish leaders. Paul seems more upset that Peter's actions caused other new-Christians to change their ways without them knowing why.

The hardest thing to do is confront someone else who is doing something contrary to the Gospel. Paul here seems to address Peter to his face and then later in front of everyone. I think we fail to be this bold because we might offend someone else or even bring to light some inequities of our own.

My prayer is that I am bold when speaking the truth of the Gospel just as Paul was here!