Hebrews 10:26

for if we wilfully apostatize, after having received the knowledge of the truth, it is as a sin for which there is no sacrifice appointed.

2 Peter 2:20-22

As for those who have renounc'd the pollutions of the world, by their owning Jesus Christ for their Lord and saviour, if they are prevail'd upon to be entangled therein again, their last state is worse than the first.

1 John 5:16

If any man see his brother commit a sin, which is not a mortal sin, let him pray to God, who will grant him life, for such as do not commit a mortal sin. there is a sin unto death: in which case I do not enjoin any prayer to be made.

Luke 12:47

but the servant, who knows his master's will, and prepares not himself, nor executes his orders, shall receive many stripes.

John 9:41

Jesus said to them, if you were blind, you would be excusable; but since you own that you see, you stand convicted.

John 13:17

if ye comprehend these things, happy are ye if ye put them in practice.

John 15:22-24

if I had not appear'd, and inform'd them, they would have been innocent: but now they have no excuse for their sin.

2 Thessalonians 2:10

and with all the vile methods of imposture, to the ruin of those, who are averse to the truth, by which they might be saved.

1 Timothy 1:13

who was before a blasphemer, and a violent persecutor; but I obtained mercy, because I acted thro' ignorance in incrudelity.

Hebrews 6:4-6

For it is impossible for those who were once enlightned, and have received the heavenly gifts, communicated by the holy spirit,

Matthew 12:43-45

When an unclean spirit is gone out of a man, he roams about the deserts, seeking rest, and findeth none.

Matthew 12:31-32

wherefore I declare to you, all manner of sin and blasphemy shall be forgiven men; but blaspheming the holy Spirit

James 4:17

he then that knows what is virtuous, and does not practise it, is a criminal.

Treasury of Scripture Knowledge

Summary

For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,

Bible References

If

Hebrews 6:4
For it is impossible for those who were once enlightned, and have received the heavenly gifts, communicated by the holy spirit,
Matthew 12:31
wherefore I declare to you, all manner of sin and blasphemy shall be forgiven men; but blaspheming the holy Spirit
John 9:41
Jesus said to them, if you were blind, you would be excusable; but since you own that you see, you stand convicted.
1 Timothy 1:13
who was before a blasphemer, and a violent persecutor; but I obtained mercy, because I acted thro' ignorance in incrudelity.
2 Peter 2:20
As for those who have renounc'd the pollutions of the world, by their owning Jesus Christ for their Lord and saviour, if they are prevail'd upon to be entangled therein again, their last state is worse than the first.
1 John 5:16
If any man see his brother commit a sin, which is not a mortal sin, let him pray to God, who will grant him life, for such as do not commit a mortal sin. there is a sin unto death: in which case I do not enjoin any prayer to be made.

General references

Matthew 7:27
the rain descends, the flood rushes on, the winds blow, and beat upon the house: down it falls, and wide are its ruins.
Matthew 24:21
for the desolation will be so dreadful, the like was never seen since the beginning of the world, no, nor ever shall be again.
Mark 3:28
I declare unto you, all the sins which men may commit, and whatsoever blasphemies they may utter, may be forgiven them.
Luke 12:10
and whoever shall cast a reflection upon the son of man, it shall be forgiven him; but as for him, that shall blaspheme the holy spirit, it shall not be forgiven.