'Warn' in the Bible

I will warn you whom to fear: fear him who after killing has power to throw into Gehenna: yes, I say to you, fear him.

For I have five brothers. Let him earnestly warn them, lest they also come to this place of torment.'

For through the authority graciously given to me I warn every individual among you not to value himself unduly, but to cultivate sobriety of judgement in accordance with the amount of faith which God has allotted to each one.

Yet of this I warn you, brethren: the time has been shortened--so that henceforth those who have wives should be as though they had none,

Therefore I warn you, and I implore you in the name of the Master, no longer to live as the Gentiles in their perverseness live,

If you warn the brethren of these dangers you will be a good and faithful servant of Christ Jesus, inwardly feeding on the lessons of the faith and of the sound teaching of which you have been, and are, so close a follower.