Hebrews 10:26

Remember, if we sin willfully after we have gained a full knowledge of the Truth, there can be no further sacrifice for sin;

2 Peter 2:20-22

If, after having escaped the polluting influences of the world, through knowing our Lord and Savior, Jesus Christ, men are again entangled in them, and give way to them, their last state has become worse than their first.

1 John 5:16

If any one sees his Brother committing some sin that is not a deadly sin, he will ask, and so be the means of giving Life to him--to any whose sin is not deadly. There is such a thing as deadly sin; about that I do not say that a man should pray.

Luke 12:47

The servant who knows his master's wishes and yet does not prepare and act accordingly will receive many lashes;

John 9:41

"If you had been blind," replied Jesus, "you would have had no sin to answer for; but, as it is, you say 'We can see,' and so your sin remains.

John 13:17

Now that you know these things, happy are you if you do them.

John 15:22-24

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

2 Thessalonians 2:10

to the ruin of those who are on the path to destruction, because they have never received and loved the Truth to their own Salvation.

1 Timothy 1:13

though I once used to blaspheme, and to persecute, and to insult. Yet mercy was shown me, because I acted in ignorance, while still an unbeliever;

Hebrews 6:4-6

For if those who were once for all brought into the Light, and learned to appreciate the gift from Heaven, and came to share in the Holy Spirit,

Matthew 12:43-45

No sooner does a foul spirit leave a man, than it passes through places where there is no water, in search of rest, and does not find it.

Matthew 12:31-32

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

James 4:17

He, then, who knows what is right but fails to do it--that is sin in him.

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 if those who were once for all brought into the Light, and learned to appreciate the gift from Heaven, and came to share in the Holy Spirit,
Matthew 12:31
Therefore, I tell you, men will be forgiven every sin and slander; but slander against the Holy Spirit will not be forgiven.
John 9:41
"If you had been blind," replied Jesus, "you would have had no sin to answer for; but, as it is, you say 'We can see,' and so your sin remains.
1 Timothy 1:13
though I once used to blaspheme, and to persecute, and to insult. Yet mercy was shown me, because I acted in ignorance, while still an unbeliever;
2 Peter 2:20
If, after having escaped the polluting influences of the world, through knowing our Lord and Savior, Jesus Christ, men are again entangled in them, and give way to them, their last state has become worse than their first.
1 John 5:16
If any one sees his Brother committing some sin that is not a deadly sin, he will ask, and so be the means of giving Life to him--to any whose sin is not deadly. There is such a thing as deadly sin; about that I do not say that a man should pray.

General references

Matthew 7:27
The rain poured down, the rivers rose, the winds blew and struck against that house, and it fell; and great was its downfall."
Matthew 24:21
for that will be 'a time of great distress, the like of which has not occurred from the beginning of the world down to the present time'--no, nor ever will again.
Mark 3:28
I tell you that men will be forgiven everything--their sins, and all the slanders that they utter;
Luke 12:10
Every one who shall say anything against the Son of Man will be forgiven, but for him who slanders the Holy Spirit there will be no forgiveness.