Galatians 2:14

But, when I saw that they were not dealing straightforwardly with the Truth of the Good News, I said to Peter, before them all, "If you, who were born a Jew, adopt Gentile customs, instead of Jewish, why are you trying to compel the Gentile converts to adopt Jewish customs?"

Matthew 18:15

If your Brother does wrong, go to him and convince him of his fault when you and he are alone. If he listens to you, you have won your Brother.

1 Timothy 5:20

but rebuke offenders publicly, so that others may take warning.

Treasury of Scripture Knowledge

Summary

Open rebuke is better than secret love.

Bible References

General references

Matthew 18:15
If your Brother does wrong, go to him and convince him of his fault when you and he are alone. If he listens to you, you have won your Brother.
Galatians 2:14
But, when I saw that they were not dealing straightforwardly with the Truth of the Good News, I said to Peter, before them all, "If you, who were born a Jew, adopt Gentile customs, instead of Jewish, why are you trying to compel the Gentile converts to adopt Jewish customs?"
1 Timothy 5:20
but rebuke offenders publicly, so that others may take warning.