Hebrews 10:26

For if we do evil on purpose after we have had the knowledge of what is true, there is no more offering for sins,

2 Peter 2:20-22

For if, after they have got free from the unclean things of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again taken in the net and overcome, their last condition is worse than their first.

1 John 5:16

If a man sees his brother doing a sin which is not bad enough for death, let him make a prayer to God, and God will give life to him whose sin was not bad enough for death. There is a sin whose punishment is death: I do not say that he may make such a request then.

Leviticus 4:2

Say to the children of Israel: These are the offerings of anyone who does wrong through error, doing any of the things which by the Lord's order are not to be done:

Leviticus 4:13

And if all the people of Israel do wrong, without anyone's knowledge; if they have done any of the things which by the Lord's order are not to be done, causing sin to come on them;

Numbers 15:28-31

And the priest will take away the sin of the person who has done wrong, if the wrong was done unconsciously, and he will have forgiveness.

Deuteronomy 17:12

And any man who, in his pride, will not give ear to the priest whose place is there before the Lord your God, or to the judge, is to be put to death: you are to put away the evil from Israel.

Daniel 5:22-23

And you, his son, O Belshazzar, have not kept your heart free from pride, though you had knowledge of all this;

Luke 12:47

And the servant who had knowledge of his lord's desires and was not ready for him and did not do as he was ordered, will be given a great number of blows;

John 9:41

Jesus said to them, If you were blind you would have no sin: but now that you say, We see; your sin is there still.

John 13:17

If these things are clear to you, happy are you if you do them.

John 15:22-24

If I had not come and been their teacher they would have had no sin: but now they have no reason to give for their sin.

2 Thessalonians 2:10

And with every deceit of wrongdoing among those whose fate is destruction; because they were quite without that love of the true faith by which they might have salvation.

1 Timothy 1:13

Though I had said violent words against God, and done cruel acts, causing great trouble: but I was given mercy, because I did it without knowledge, not having faith;

Hebrews 6:4-6

As for those who at one time saw the light, tasting the good things from heaven, and having their part in the Holy Spirit,

Matthew 12:43-45

But the unclean spirit, when he is gone out of a man, goes through dry places looking for rest, and getting it not.

Psalm 19:12-13

Who has full knowledge of his errors? make me clean from secret evil.

Matthew 12:31-32

So I say to you, Every sin and every evil word against God will have forgiveness; but for evil words against the Spirit there will be no forgiveness.

James 4:17

The man who has knowledge of how to do good and does not 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
As for those who at one time saw the light, tasting the good things from heaven, and having their part in the Holy Spirit,
Leviticus 4:2
Say to the children of Israel: These are the offerings of anyone who does wrong through error, doing any of the things which by the Lord's order are not to be done:
Numbers 15:28
And the priest will take away the sin of the person who has done wrong, if the wrong was done unconsciously, and he will have forgiveness.
Deuteronomy 17:12
And any man who, in his pride, will not give ear to the priest whose place is there before the Lord your God, or to the judge, is to be put to death: you are to put away the evil from Israel.
Psalm 19:12
Who has full knowledge of his errors? make me clean from secret evil.
Daniel 5:22
And you, his son, O Belshazzar, have not kept your heart free from pride, though you had knowledge of all this;
Matthew 12:31
So I say to you, Every sin and every evil word against God will have forgiveness; but for evil words against the Spirit there will be no forgiveness.
John 9:41
Jesus said to them, If you were blind you would have no sin: but now that you say, We see; your sin is there still.
1 Timothy 1:13
Though I had said violent words against God, and done cruel acts, causing great trouble: but I was given mercy, because I did it without knowledge, not having faith;
2 Peter 2:20
For if, after they have got free from the unclean things of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again taken in the net and overcome, their last condition is worse than their first.
1 John 5:16
If a man sees his brother doing a sin which is not bad enough for death, let him make a prayer to God, and God will give life to him whose sin was not bad enough for death. There is a sin whose punishment is death: I do not say that he may make such a request then.

General references

Deuteronomy 18:19
And whoever does not give ear to my words which he will say in my name, will be responsible to me.
Matthew 7:27
And the rain came down and there was a rush of waters and the winds were driving against that house; and it came down and great was its fall.
Matthew 24:21
Because in those days there will be great sorrow, such as there has not been from the start of the world till now, or ever will be.
Mark 3:28
Truly, I say to you, The sons of men will have forgiveness for all their sins and for all the evil words they say:
Luke 12:10
And if anyone says a word against the Son of man, he will have forgiveness: but for him who says evil words against the Holy Spirit, there will be no forgiveness.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain