Hebrews 10:26

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

2 Peter 2:20-22

For if they, after they have escaped from the filthiness of the world through the knowledge of the Lord, and of the saviour Jesus Christ, they are yet tangled again therein and overcome: then is the latter end worse with them than the beginning.

1 John 5:16

If any man see his brother sin a sin that is not to death, let him ask, and he shall give him life for them that sin not unto death. There is a sin unto death, for which say I not that a man should pray.

Leviticus 4:2

"Speak unto the children of Israel and say, 'When a soul sinneth through ignorance, and hath done any of those things which the LORD hath forbidden in his commandments to be done:

Leviticus 4:13

"'If the whole commonalty of the children of Israel sin through ignorance, and the thing be hid from their eyes: so that they have committed any of these things which the LORD hath forbidden to be done in his commandments and have offended,

Numbers 15:28-31

And the priest shall make an atonement for the soul that sinned ignorantly with the sin offering before the LORD and reconcile him, and it shall be forgiven him.

Deuteronomy 17:12

And that man that will do presumptuously, so that he will not hearken unto the priest that standeth there to minister unto the LORD thy God or unto the judge, shall die: and so thou shalt put away evil from Israel.

Daniel 5:22-23

And thou, his son, O Belshazzar, for all this, hast not submitted thine heart, though thou knewest all these things:

Luke 12:47

The servant that knew his master's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes.

John 9:41

Jesus said unto them, "If ye were blind, ye should have no sin: but now ye say, 'We see.' Therefore your sin remaineth."

John 13:17

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

John 15:22-24

If I had not come and spoken unto them, they should not have had sin: but now have they nothing to cloak their sin withal.

2 Thessalonians 2:10

and in all deceivableness of unrighteousness, among them that perish: because they received not the love of the truth, that they might have been saved.

1 Timothy 1:13

when before I was a blasphemer, and a persecutor, and a tyrant. But I obtained mercy because I did it ignorantly, through unbelief:

Hebrews 6:4-6

For it is not possible that they which were once lighted, and have tasted of the heavenly gift, and were become partakers of the holy ghost,

Matthew 12:43-45

When the unclean spirit is gone out of a man, he walketh throughout dry places, seeking rest, and findeth none.

Psalm 19:12-13

Who can tell how oft he offendeth? O cleanse thou me from my secret faults.

Matthew 12:31-32

Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men, but the blasphemy of the spirit shall not be forgiven unto men.

James 4:17

Therefore to him that knoweth how 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
For it is not possible that they which were once lighted, and have tasted of the heavenly gift, and were become partakers of the holy ghost,
Leviticus 4:2
"Speak unto the children of Israel and say, 'When a soul sinneth through ignorance, and hath done any of those things which the LORD hath forbidden in his commandments to be done:
Numbers 15:28
And the priest shall make an atonement for the soul that sinned ignorantly with the sin offering before the LORD and reconcile him, and it shall be forgiven him.
Deuteronomy 17:12
And that man that will do presumptuously, so that he will not hearken unto the priest that standeth there to minister unto the LORD thy God or unto the judge, shall die: and so thou shalt put away evil from Israel.
Psalm 19:12
Who can tell how oft he offendeth? O cleanse thou me from my secret faults.
Daniel 5:22
And thou, his son, O Belshazzar, for all this, hast not submitted thine heart, though thou knewest all these things:
Matthew 12:31
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men, but the blasphemy of the spirit shall not be forgiven unto men.
John 9:41
Jesus said unto them, "If ye were blind, ye should have no sin: but now ye say, 'We see.' Therefore your sin remaineth."
1 Timothy 1:13
when before I was a blasphemer, and a persecutor, and a tyrant. But I obtained mercy because I did it ignorantly, through unbelief:
2 Peter 2:20
For if they, after they have escaped from the filthiness of the world through the knowledge of the Lord, and of the saviour Jesus Christ, they are yet tangled again therein and overcome: then is the latter end worse with them than the beginning.
1 John 5:16
If any man see his brother sin a sin that is not to death, let him ask, and he shall give him life for them that sin not unto death. There is a sin unto death, for which say I not that a man should pray.

General references

Deuteronomy 18:19
And whosoever will not hearken unto the words which he shall speak in my name, I will require it of him.
Matthew 7:27
And abundance of rain descended, and the floods came, and the winds blew, and beat upon that house, and it fell: and great was the fall of it.
Matthew 24:21
For then shall be great tribulation, such as was not from the beginning of the world to this time, nor shall be.
Mark 3:28
Verily I say unto you, All sins shall be forgiven unto men's children: and blasphemy, wherewith they blaspheme:
Luke 12:10
And whosoever speaketh a word against the son of man, it shall be forgiven him. But unto him that blasphemeth the holy ghost, it shall not be forgiven.