The saints in the Old Testament looked forward to the day when God would forgive sins in His great love and mercy:

Psalm 130:3-4
If you, Lord, kept a record of sins, Lord, who could stand?
But with you there is forgiveness, so that we can, with reverence, serve you.

Micah 7 :18-19
Who is a God like you, who pardons sin and forgives the transgression of the remnant of his inheritance? You do not stay angry forever but delight to show mercy.
You will again have compassion on us; you will tread our sins underfoot
    and hurl all our iniquities into the depths of the sea.”

Our sins were cast into the sea – just like Jonah was in the sea for 3 days. Jesus said that His death and resurrection would be like the sign of Jonah – When Jesus died on the cross, our sins were forgiven, and they were taken away – buried in the tomb. He rose from the dead without our sins, declaring us righteous if we believe.

This is why David said that our sins are taken away as far as east is from the west:
Psalm 103 “10 he does not treat us as our sins deserve or repay us according to our iniquities.
11 For as high as the heavens are above the earth, so great is his love for those who fear him; 12 as far as the east is from the west, so far has he removed our transgressions from us.”

Job looked forward to the New Covenant of Jesus Christ.
Job 14 “If someone dies, will they live again? All the days of my hard service. I will wait for my renewal to come. 15 You will call and I will answer you; you will long for the creature your hands have made. Surely then you will count my steps but not keep track of my sin. My offenses will be sealed up in a bag; you will cover over my sin.”

Job said that God would call us in great love/longing. This is exactly what Jesus said will happen on the last day.

John 5 “28 “Do not be amazed at this, for a time is coming when all who are in their graves will hear his voice 29 and come out”

1 Thessalonians 4 “16 For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. 17 After that, we who are still alive and are left will be caught up together with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever.”

The believers’ sins will not be remembered thanks to Jesus.
Jeremiah also looked forward to the New Covenant in Christ.

Jeremiah 31 ““The days are coming,” declares the Lord, “when I will make a new covenant…“For I will forgive their wickedness and will remember their sins no more.”

Thank you Jesus that you have made it happen.
Our sins will never be remembered anymore thanks to faith in Jesus’ finished work on the cross.