Why is Christ's statement 'It is finished' important?

In John 19:30, Jesus utters the powerful phrase 'It is finished' just before His death on the cross. This declaration assures us that His sacrificial work to atone for our sins is complete. It signifies that all the demands of the law have been satisfied and that believers can rest in the finished nature of the redemptive work of Christ. It eliminates the need for any further sacrifices or works on our part for salvation, underscoring that salvation is solely by grace through faith in Him. This powerful assurance is an essential tenet of sovereign grace theology.