Galatians 2:14
But, when I saw that they did not act in harmony with [the principles of] the truth of the Gospel [message], I said to Cephas in front of everyone, "If you, being a Jew, act like a Gentile [by showing such discrimination], how do you expect to persuade Gentiles to live like Jews [i.e., like Christian Jews who are taught to love all people]?"
Matthew 18:15
"And if your brother sins against you, go and show him where he wronged you, [but] keep it between just the two of you. If he listens to you [i.e., accepts your reasoning and repents], you have won your brother [back].
1 Timothy 5:20
You should rebuke in front of everyone [in the church] those elders who continue to sin, so that the rest [of the congregation] will be afraid [of sinning].