Hebrews 6:6

and then fell away, it is impossible to renew them again to repentance; seeing they crucify the Son of God for themselves again, and put him to open shame.

Hebrews 10:29

How much worse punishment, do you think, will he be judged worthy of, who has trodden under foot the Son of God, and has counted the blood of the covenant with which he was sanctified an unholy thing, and has insulted the Spirit of grace?

Hebrews 6:4

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

2 Peter 2:21

For it would be better for them not to have known the way of righteousness, than, after knowing it, to turn back from the holy commandment delivered to them.

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 do not say that he should make a request concerning this.

Psalm 51:10

Create in me a clean heart, O God. Renew a right spirit within me.

Isaiah 1:28

But the destruction of transgressors and sinners shall be together, and those who forsake the LORD shall be consumed.

Zechariah 12:10-14

I will pour on the house of David, and on the inhabitants of Jerusalem, the spirit of grace and of supplication; and they will look to me whom they have pierced; and they shall mourn for him, as one mourns for his only son, and will grieve bitterly for him, as one grieves for his firstborn.

Matthew 19:26

Looking at them, Jesus said, "With men this is impossible, but with God all things are possible."

Matthew 23:31-32

Therefore you testify to yourselves that you are children of those who killed the prophets.

Matthew 27:38-44

Then there were two robbers crucified with him, one on his right hand and one on the left.

Luke 11:48

So you are witnesses and consent to the works of your fathers. For they killed them, and you build their tombs.

Luke 23:35-39

The people stood watching. The rulers also scoffed at him, saying, "He saved others. Let him save himself, if this is the Messiah of God, his Chosen One."

2 Timothy 2:25

in gentleness correcting those who oppose him: perhaps God may give them repentance leading to a full knowledge of the truth,

Hebrews 12:2

looking to Jesus, the author and finisher of our faith, who for the joy that was set before him endured the cross, disregarding its shame, and has sat down at the right hand of the throne of God.

Treasury of Scripture Knowledge

Summary

If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.

Bible References

To renew

Hebrews 6:4
For concerning those who were once enlightened and tasted of the heavenly gift, and were made partakers of the Holy Spirit,
Psalm 51:10
Create in me a clean heart, O God. Renew a right spirit within me.
Isaiah 1:28
But the destruction of transgressors and sinners shall be together, and those who forsake the LORD shall be consumed.
2 Timothy 2:25
in gentleness correcting those who oppose him: perhaps God may give them repentance leading to a full knowledge of the truth,

They crucify

Hebrews 10:29
How much worse punishment, do you think, will he be judged worthy of, who has trodden under foot the Son of God, and has counted the blood of the covenant with which he was sanctified an unholy thing, and has insulted the Spirit of grace?
Zechariah 12:10
I will pour on the house of David, and on the inhabitants of Jerusalem, the spirit of grace and of supplication; and they will look to me whom they have pierced; and they shall mourn for him, as one mourns for his only son, and will grieve bitterly for him, as one grieves for his firstborn.
Matthew 23:31
Therefore you testify to yourselves that you are children of those who killed the prophets.
Luke 11:48
So you are witnesses and consent to the works of your fathers. For they killed them, and you build their tombs.

An open

Hebrews 12:2
looking to Jesus, the author and finisher of our faith, who for the joy that was set before him endured the cross, disregarding its shame, and has sat down at the right hand of the throne of God.
Matthew 27:38
Then there were two robbers crucified with him, one on his right hand and one on the left.
Luke 23:35
The people stood watching. The rulers also scoffed at him, saying, "He saved others. Let him save himself, if this is the Messiah of God, his Chosen One."

General references

Leviticus 14:43
"If the plague comes again, and breaks out in the house, after he has taken out the stones, and after he has scraped the house, and after it was plastered;
Mark 3:28
Truly I tell you, all sins of the sons of men 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.
Luke 14:30
saying, 'This man began to build, and was not able to finish.'
1 Peter 2:3
if indeed you have tasted that the Lord is gracious:
Jude 1:22
On some have compassion, who are in doubt,