Luke 12:5

but I will inform you whom you should fear: fear him, who after he has kill'd, has power to precipitate into hell; yes, I advise you, fear him.

Matthew 10:28

fear not those who can only kill the body, but cannot hurt the soul: rather fear him who is able to destroy both soul and body in Gehenna.

2 Peter 2:4

for since God did not spare the angels, who had sinned, but having precipitated them to hell, confin'd them to chains of darkness, where they are reserv'd for judgment:

Matthew 5:22

but I say unto you, that whosoever is angry with his brother without a cause, shall be punish'd by the tribunal: and whosoever shall say to his brother, Raca, shall be punish'd by the Sanhedrim: but whosoever shall say, thou fool, shall be punish'd by the fire of Gehenna.

Matthew 25:41

then will he say to those on the left, depart from me ye cursed, into everlasting fire, prepared for the devil and his angels.

Matthew 25:46

and these shall go away into everlasting punishment: but the righteous into life eternal.

Mark 13:23

be you therefore upon your guard: remember I have forewarned you against all events.

1 Thessalonians 4:6

that no man should be exorbitant, and behave contumeliously to his brother: because the Lord is the avenger of all such crimes, as we have formerly remonstrated to you.

Hebrews 10:31

it is a terrible thing to fall into the hands of the living God.

Revelation 14:7

"fear the Lord, and give glory to him, for the hour of his judgment is come: adore therefore him that made the heaven, the earth, the sea, and the fountains."

Revelation 15:4

who will not fear thee, O Lord, and glorify thy name? for thou only art holy: and all nations shall come to adore thee; because thy judgments have been display'd."

Revelation 20:14

and death and the grave were cast into the lake of fire: this is the second death.

Treasury of Scripture Knowledge

Summary

But I will forewarn you whom ye shall fear: Fear him, which after he hath killed hath power to cast into hell; yea, I say unto you, Fear him.

Bible References

Forewarn

Mark 13:23
be you therefore upon your guard: remember I have forewarned you against all events.
1 Thessalonians 4:6
that no man should be exorbitant, and behave contumeliously to his brother: because the Lord is the avenger of all such crimes, as we have formerly remonstrated to you.

Power

Matthew 10:28
fear not those who can only kill the body, but cannot hurt the soul: rather fear him who is able to destroy both soul and body in Gehenna.
Matthew 25:41
then will he say to those on the left, depart from me ye cursed, into everlasting fire, prepared for the devil and his angels.
2 Peter 2:4
for since God did not spare the angels, who had sinned, but having precipitated them to hell, confin'd them to chains of darkness, where they are reserv'd for judgment:
Revelation 20:14
and death and the grave were cast into the lake of fire: this is the second death.