Hebrews 10:26

For if we sin willfully after we have received the knowledge of the truth, there remains no more a sacrifice for sins,

2 Peter 2:20-22

For if, after they have escaped the defilement of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in it and overcome, the last state has become worse for them than the first.

1 John 5:16

If anyone sees his brother sinning a sin not leading to death, he shall ask, and God will give him life for those who sin not leading to death. There is a sin leading to death. I don't say that he should make a request concerning this.

Leviticus 4:2

"Speak to the children of Israel, saying, 'If anyone sins unintentionally, in any of the things which Yahweh has commanded not to be done, and does any one of them:

Leviticus 4:13

"'If the whole congregation of Israel sins, and the thing is hidden from the eyes of the assembly, and they have done any of the things which Yahweh has commanded not to be done, and are guilty;

Numbers 15:28-31

The priest shall make atonement for the soul who errs, when he sins unwittingly, before Yahweh, to make atonement for him; and he shall be forgiven.

Deuteronomy 17:12

The man who does presumptuously, in not listening to the priest who stands to minister there before Yahweh your God, or to the judge, even that man shall die: and you shall put away the evil from Israel.

Daniel 5:22-23

You, his son, Belshazzar, have not humbled your heart, though you knew all this,

Luke 12:47

That servant, who knew his lord's will, and didn't prepare, nor do what he wanted, will be beaten with many stripes,

John 9:41

Jesus said to them, "If you were blind, you would have no sin; but now you say, 'We see.' Therefore your sin remains.

John 13:17

If you know these things, blessed are you if you do them.

John 15:22-24

If I had not come and spoken to them, they would not have had sin; but now they have no excuse for their sin.

2 Thessalonians 2:10

and with all deception of wickedness for those who are being lost, because they didn't receive the love of the truth, that they might be saved.

1 Timothy 1:13

although I was before a blasphemer, a persecutor, and insolent. However, I obtained mercy, because I did it ignorantly in unbelief.

Hebrews 6:4-6

For concerning those who were once enlightened and tasted of the heavenly gift, and were made partakers of the Holy Spirit,

Matthew 12:43-45

But the unclean spirit, when he is gone out of the man, passes through waterless places, seeking rest, and doesn't find it.

Psalm 19:12-13

Who can discern his errors? Forgive me from hidden errors.

Matthew 12:31-32

Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men.

James 4:17

To him therefore who knows to do good, and doesn't do it, 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
For concerning those who were once enlightened and tasted of the heavenly gift, and were made partakers of the Holy Spirit,
Leviticus 4:2
"Speak to the children of Israel, saying, 'If anyone sins unintentionally, in any of the things which Yahweh has commanded not to be done, and does any one of them:
Numbers 15:28
The priest shall make atonement for the soul who errs, when he sins unwittingly, before Yahweh, to make atonement for him; and he shall be forgiven.
Deuteronomy 17:12
The man who does presumptuously, in not listening to the priest who stands to minister there before Yahweh your God, or to the judge, even that man shall die: and you shall put away the evil from Israel.
Psalm 19:12
Who can discern his errors? Forgive me from hidden errors.
Daniel 5:22
You, his son, Belshazzar, have not humbled your heart, though you knew all this,
Matthew 12:31
Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men.
John 9:41
Jesus said to them, "If you were blind, you would have no sin; but now you say, 'We see.' Therefore your sin remains.
1 Timothy 1:13
although I was before a blasphemer, a persecutor, and insolent. However, I obtained mercy, because I did it ignorantly in unbelief.
2 Peter 2:20
For if, after they have escaped the defilement of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in it and overcome, the last state has become worse for them than the first.
1 John 5:16
If anyone sees his brother sinning a sin not leading to death, he shall ask, and God will give him life for those who sin not leading to death. There is a sin leading to death. I don't say that he should make a request concerning this.

General references

Deuteronomy 18:19
It shall happen, that whoever will not listen to my words which he shall speak in my name, I will require it of him.
Matthew 7:27
The rain came down, the floods came, and the winds blew, and beat on that house; and it fell -- and great was its fall."
Matthew 24:21
for then there will be great oppression, such as has not been from the beginning of the world until now, no, nor ever will be.
Mark 3:28
Most certainly I tell you, all sins of the descendants of man will be forgiven, including their blasphemies with which they may blaspheme;
Luke 12:10
Everyone who speaks a word against the Son of Man will be forgiven, but those who blaspheme against the Holy Spirit will not be forgiven.