What does the Bible say about substitution and satisfaction in salvation?

In Isaiah 53, we read about the suffering servant whose death exemplifies both substitution and satisfaction. Christ did not merely make salvation a possibility; He accomplished it, serving as the substitute for His people by bearing their iniquities. His suffering and death fulfill the righteous requirements of God's justice, ensuring that all for whom He died are saved absolutely. This is a core tenet of Reformed theology, affirming that Jesus' death fully atones for the sins of the elect, providing assurance of salvation without doubt.