We believe that those made a new creation in Christ are now no longer slaves to sin and are set free for good works. They are made right with God apart from their own works by the work of Christ on the cross. The Holy Spirit recreates them to be eager for good works.
This is a powerful depiction of the crucifixion, different than many you've probably seen. Consider how horrific and grisly Grunewald's depiction is of Christ's suffering the penalty of death.