The Lord promises that He will remember our sins no more

When we know the Lord, we receive the forgiveness of sins. We know Him as the God of Grace, who overlooks our transgressions. What a happy discovery this is!

But how divinely expressed this promise is: the Lord promises that He will remember our sins no more! Can God forget? He says He will, and He means what He says. He will consider it as if we had never sinned. The great Atonement so effectively removed all sin, that to the mind of God it is as if it did not exist. The believer is now as accepted in Christ Jesus as Adam was in his innocence; yes, even more so, for he wears divine justice, while Adam's was only human.

The Great Lord will not remember our sins to punish them, or to love us a bit less because of those sins. Like a debt that, when paid, ceases to be a debt, so the Lord makes a complete cancellation of the iniquity of His people.

When we are lamenting over our transgressions and shortcomings - and this is our duty as long as we live - at the same time we are to rejoice that they will never be mentioned against us. This leads us to hate sin. God's unmerited forgiveness leads us to be vigilant so that we never again offend him through disobedience.

Source: The Bank of Faith Checkbook. Translation by Allan Roman.

http://www.spurgeon.com.mx/chequera/meditames/abril.pdf