Verses with the word warn in the New Testament (3 verses):
Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears.
1 Corinthians 4:14
I write not these things to shame you, but as my beloved sons I warn you.
1 Thessalonians 5:14
Now we exhort you, brethren, warn them that are unruly, comfort the feebleminded, support the weak, be patient toward all men.