Something can’t be paid for and forgiven simultaneously. Your sins are either forgiven or your sins were paid for. Forgiveness is given, freedom is paid for. The cross was not about forgiveness, it was about payment for freedom from sin. Wages of sin is death. Jesus’s death paid the legal note of indebtedness that Satan had, to hold us in bondage. Jesus took away his leverage. The cross cancels the legal power of indebtedness to the enemy.
Col 2:13 When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions,14 having canceled out the certificate of debt consisting of decrees against us, which was hostile to us; and He has taken it out of the way, having nailed it to the cross.