'Warn' in the Bible

But I will point out to you whom you should fear: fear the One who, after He has killed, has authority and power to hurl [you] into hell; yes, I say to you, [stand in great awe of God and] fear Him!

for I have five brothers—in order that he may solemnly warn them and witness to them, so that they too will not come to this place of torment.’