Acts 20:31

Therefore, be on your guard, remembering how for three years, night and day, I never ceased, even with tears, to warn each one of you.

1 Thessalonians 5:14

We entreat you also, Brothers--warn the disorderly, comfort the faint-hearted, give a helping hand to the weak, and be patient with every one.

Treasury of Scripture Knowledge

Summary

And what cause soever shall come to you of your brethren that dwell in their cities, between blood and blood, between law and commandment, statutes and judgments, ye shall even warn them that they trespass not against the LORD, and so wrath come upon you, and upon your brethren: this do, and ye shall not trespass.

Bible References

Warn them

Acts 20:31
Therefore, be on your guard, remembering how for three years, night and day, I never ceased, even with tears, to warn each one of you.
1 Thessalonians 5:14
We entreat you also, Brothers--warn the disorderly, comfort the faint-hearted, give a helping hand to the weak, and be patient with every one.