Why is understanding the truth of substitution important for Christians?

The truth of substitution is vital for Christians because it provides clarity on God's plan for salvation. It reconciles the just nature of God with His mercy towards sinners. When Christ died as a substitute for the elect, He fulfilled God's demands for justice while simultaneously providing a means of grace for those who believe. This doctrine assures believers that their sins are fully paid for and that they stand justified before God not on their own merit, but because of Christ's sacrificial death. As a result, Christians can have peace and assurance in their salvation, knowing that the penalty for sin has been borne by another, enabling a relationship with God.