Indeed, many individuals in the Bible claim personal assurance of their own salvation. Assurance was a product of Paul's ministry. There is no doubt that Old and New Testament believers possessed the assurance of their salvation. He said that, seven centuries before Calvary, Isaiah prophesied in chapter 53 how God's righteousness would be revealed in Christ's gospel to provide assurance to all who believe. The first debit entry takes into account our participation in the fall of the race.
Sheep follow the leader.
But the second entry takes into account our individual willfulness. By His sacrificial death on the cross, He has paid to outraged justice that which meets every charge against the sinner. Now in perfect righteousness God can offer a complete pardon and justification to all who trust His risen Son. The troubled conscience can now be at rest. God is satisfied with what His Son has done.