How do we know salvation is truly accomplished by Christ?

The assurance of salvation through Christ is rooted in His completed work on the cross. Romans 8:32 declares that God did not spare His own Son, emphasizing the depth of Christ's sacrifice for humanity. This truth is further underscored in Hebrews 9, where it's stated that Jesus, with His sacrifice, has put away sin once and for all. The declaration 'It is finished' signifies that all necessary work for salvation has been done by Christ, and believers are justified freely by His grace.