Acts 20:31

So, be very watchful, and remember that for three years I never stopped warning every one of you [about such matters] both night and day with tears [in my eyes].

1 Thessalonians 5:14

And we urge you, brothers, to warn those who are idle [Note: The word "idle" originally meant, "insubordinate, or unruly." See II Thess. 3:6-7, 11], encourage those who are timid, help the [spiritually] weak and be patient with everyone.

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
So, be very watchful, and remember that for three years I never stopped warning every one of you [about such matters] both night and day with tears [in my eyes].
1 Thessalonians 5:14
And we urge you, brothers, to warn those who are idle [Note: The word "idle" originally meant, "insubordinate, or unruly." See II Thess. 3:6-7, 11], encourage those who are timid, help the [spiritually] weak and be patient with everyone.