Hebrews 10:26

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

2 Peter 2:20-22

For if, after they had escaped the pollutions of the world, through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled and vanquished by them, their last state is worse than the first;

1 John 5:16

If any one see his brother commit a sin which is not unto death, let him pray for him, and God will give him life, that is for them that do not sin unto death. There is a sin unto death: and for that I do not say that he should pray.

Luke 12:47

And that servant, who knew his master's will, and did not prepare himself to do according to his will, shall be beaten with many stripes;

John 9:41

Jesus replied, If ye were blind, ye would not have sin: but now ye say, We see; your sin therefore remaineth.

John 13:17

If ye know these things, happy are ye, if ye do them.

John 15:22-24

If I had not come and spoken unto them, they had not had sin: but now they have no excuse for their sin.

2 Thessalonians 2:10

and wonders, and with all iniquitous fraud, among those that shall perish; because they received not the love of the truth, by which they might be saved.

1 Timothy 1:13

who before was a blasphemer, and a persecutor, and an oppressor. But I obtained mercy, because I did it ignorantly in unbelief: and the grace of our Lord superabounded,

Hebrews 6:4-6

who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the holy Spirit,

Matthew 12:43-45

Now when an impure spirit is gone out of a man, he wanders through dry desert places, seeking rest, and findeth none:

Matthew 12:31-32

Wherefore, I tell you, All manner of sin and blasphemy shall be forgiven to men; but the blasphemy against the holy Spirit shall not be forgiven them:

James 4:17

To him therefore that knoweth to do good, and doth it not, to him it is sin.

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
who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the holy Spirit,
Matthew 12:31
Wherefore, I tell you, All manner of sin and blasphemy shall be forgiven to men; but the blasphemy against the holy Spirit shall not be forgiven them:
John 9:41
Jesus replied, If ye were blind, ye would not have sin: but now ye say, We see; your sin therefore remaineth.
1 Timothy 1:13
who before was a blasphemer, and a persecutor, and an oppressor. But I obtained mercy, because I did it ignorantly in unbelief: and the grace of our Lord superabounded,
2 Peter 2:20
For if, after they had escaped the pollutions of the world, through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled and vanquished by them, their last state is worse than the first;
1 John 5:16
If any one see his brother commit a sin which is not unto death, let him pray for him, and God will give him life, that is for them that do not sin unto death. There is a sin unto death: and for that I do not say that he should pray.

General references

Matthew 7:27
and the rain fell upon it, and the floods came, and the winds blew, and beat upon that house, and it fell, and the fall thereof was great.
Matthew 24:21
for there shall be then great affliction, such as has not been from the beginning of the world unto this time, no, nor ever shall be.
Mark 3:28
Verily I tell you, that all sins shall be forgiven to the sons of men, and blasphemies wherewith they may blaspheme:
Luke 12:10
And whosoever shall speak a word against the Son of man, it may be forgiven him; but unto him, that blasphemeth the holy Spirit, it shall not be forgiven.