Mark 3:29

but whoever blasphemes against the Holy Spirit and His power [by attributing the miracles done by Me to Satan] never has forgiveness, but is guilty of an everlasting sin [a sin which is unforgivable in this present age as well as in the age to come]”—

Matthew 25:46

Then these [unbelieving people] will go away into eternal (unending) punishment, but those who are righteous and in right standing with God [will go, by His remarkable grace] into eternal (unending) life.”

Mark 12:40

[these scribes] who devour (confiscate) widows’ houses, and offer long prayers for appearance’s sake [to impress others]. These men will receive greater condemnation.”

Luke 12:10

And everyone who speaks a word against the Son of Man, it will be forgiven him; but he who blasphemes against the Holy Spirit [that is, whoever intentionally discredits the Holy Spirit by attributing the authenticating miracles done by Me to Satan], it will not be forgiven him [for him there is no forgiveness].

Matthew 12:31-32

“Therefore I say to you, every sin and blasphemy [every evil, abusive, injurious speaking, or indignity against sacred things] will be forgiven people, but blasphemy against the [Holy] Spirit will not be forgiven.

2 Thessalonians 1:9

These people will pay the penalty and endure the punishment of everlasting destruction, banished from the presence of the Lord and from the glory of His power,

Jude 1:7

just as Sodom and Gomorrah and the adjacent cities, since they in the same way as these angels indulged in gross immoral freedom and unnatural vice and sensual perversity. They are exhibited [in plain sight] as an example in undergoing the punishment of everlasting fire.

Jude 1:13

wild waves of the sea, flinging up their own shame like foam; wandering stars, for whom the gloom of deep darkness has been reserved forever.

Treasury of Scripture Knowledge

Summary

But he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation:

General references

Bible References

But is

Mark 12:40
[these scribes] who devour (confiscate) widows’ houses, and offer long prayers for appearance’s sake [to impress others]. These men will receive greater condemnation.”
Matthew 25:46
Then these [unbelieving people] will go away into eternal (unending) punishment, but those who are righteous and in right standing with God [will go, by His remarkable grace] into eternal (unending) life.”
2 Thessalonians 1:9
These people will pay the penalty and endure the punishment of everlasting destruction, banished from the presence of the Lord and from the glory of His power,
Jude 1:7
just as Sodom and Gomorrah and the adjacent cities, since they in the same way as these angels indulged in gross immoral freedom and unnatural vice and sensual perversity. They are exhibited [in plain sight] as an example in undergoing the punishment of everlasting fire.

General references

Luke 12:10
And everyone who speaks a word against the Son of Man, it will be forgiven him; but he who blasphemes against the Holy Spirit [that is, whoever intentionally discredits the Holy Spirit by attributing the authenticating miracles done by Me to Satan], it will not be forgiven him [for him there is no forgiveness].