How do we know that Christ's work is complete for our salvation?

Christ's declaration of 'It is finished' signifies the completeness of His redemptive work (John 19:30). This assertion assures believers that all requirements for salvation were fully met by Christ's sacrifice for His elect people. In 1 Corinthians 2, Paul emphasizes the simplicity of this message—Jesus Christ and Him crucified—illustrating that salvation rests in His completed work, not on our efforts. The gospel, therefore, is good news because it emphasizes that salvation is entirely the work of Christ and not contingent upon human merit.