Mark 3:28

Verily I say unto you, All sins shall be forgiven unto the sons of men and whatever blasphemies with which they shall blaspheme,

Matthew 12:31-32

Therefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men, but the blasphemy against the Spirit shall not be forgiven unto men.

Luke 12:10

And whosoever shall speak a word against the Son of man, there is forgiveness for him; but unto him that blasphemes against the Holy Spirit, it shall not be forgiven.

1 John 5:16

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

Mark 3:28-30

Verily I say unto you, All sins shall be forgiven unto the sons of men and whatever blasphemies with which they shall blaspheme,

Hebrews 6:4-8

For it is impossible that those who once received the light and tasted of that heavenly gift and were made partakers of the Holy Spirit

Hebrews 10:26-31

For if we sin wilfully after we have received the knowledge of the truth, there remains no more sacrifice for sins,

Treasury of Scripture Knowledge

Summary

Verily I say unto you, All sins shall be forgiven unto the sons of men, and blasphemies wherewith soever they shall blaspheme:

Bible References

General references

Matthew 12:31
Therefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men, but the blasphemy against the Spirit shall not be forgiven unto men.
Luke 12:10
And whosoever shall speak a word against the Son of man, there is forgiveness for him; but unto him that blasphemes against the Holy Spirit, it shall not be forgiven.
Hebrews 6:4
For it is impossible that those who once received the light and tasted of that heavenly gift and were made partakers of the Holy Spirit
Hebrews 10:26
For if we sin wilfully after we have received the knowledge of the truth, there remains no more sacrifice for sins,
1 John 5:16
If any man see his brother sin a sin which is not unto death, he shall ask God, and he shall give him life that is, unto those that do not sin unto death. There is sin unto death, for which I do not say that you should pray.