John 20:23

Forgive sins and they are forgiven. Do not forgive sins and they are not forgiven.

Matthew 16:19

I will give you the keys of the kingdom of heaven. Whatever you declare to be improper and unlawful on earth must be what is improper and unlawful in heaven, and whatever you declare lawful on earth must be lawful in heaven.

Matthew 18:18

I tell you; whatever things are fixed by you on earth will be declared improper and unlawful in heaven. Whatever you make free on earth will be declared lawful in heaven.

Mark 2:5-10

When Jesus saw their faith, he told the man: Friend your sins are forgiven.

1 Corinthians 5:4

When you assemble in the name and with the power of our Lord Jesus Christ, I will be with you in spirit.

Acts 2:38

Then Peter said: Repent, and be baptized every one of you in the name of Jesus Christ for forgiveness of your sins, and you will receive the gift of the Holy Spirit.

Acts 10:43

All the prophets testify that through his name whoever believes in him will receive forgiveness of sins.

Acts 13:38-39

You should know, men and brothers that it is through this man Jesus the forgiveness of sins is proclaimed to you.

2 Corinthians 2:6-10

Sufficient to such a one is this punishment that was inflicted by the many.

Ephesians 2:20

You are built upon the foundation of the apostles and prophets. Christ Jesus is the chief corner stone.

1 Timothy 1:20

Among these are Hymenaeus and Alexander. I handed them over to Satan, so that they will be taught not to blaspheme.

Treasury of Scripture Knowledge

Summary

Whose soever sins ye remit, they are remitted unto them; and whose soever sins ye retain, they are retained.

Bible References

General references

Matthew 16:19
I will give you the keys of the kingdom of heaven. Whatever you declare to be improper and unlawful on earth must be what is improper and unlawful in heaven, and whatever you declare lawful on earth must be lawful in heaven.
Matthew 18:18
I tell you; whatever things are fixed by you on earth will be declared improper and unlawful in heaven. Whatever you make free on earth will be declared lawful in heaven.
Mark 2:5
When Jesus saw their faith, he told the man: Friend your sins are forgiven.
Acts 2:38
Then Peter said: Repent, and be baptized every one of you in the name of Jesus Christ for forgiveness of your sins, and you will receive the gift of the Holy Spirit.
Acts 10:43
All the prophets testify that through his name whoever believes in him will receive forgiveness of sins.
Acts 13:38
You should know, men and brothers that it is through this man Jesus the forgiveness of sins is proclaimed to you.
1 Corinthians 5:4
When you assemble in the name and with the power of our Lord Jesus Christ, I will be with you in spirit.
2 Corinthians 2:6
Sufficient to such a one is this punishment that was inflicted by the many.
Ephesians 2:20
You are built upon the foundation of the apostles and prophets. Christ Jesus is the chief corner stone.
1 Timothy 1:20
Among these are Hymenaeus and Alexander. I handed them over to Satan, so that they will be taught not to blaspheme.