How do we know the doctrine of substitution is true?

Substitution is a core tenet of the gospel, highlighting that Christ substitutes Himself for sinners, providing full satisfaction for God's justice. Biblical passages such as Isaiah 53:5 and Romans 5:8 demonstrate that Christ bore our sins in His body, suffering a penalty that we deserved. Moreover, the concept is supported by verses like Galatians 3:13 and Hebrews 9:28, which elucidate His role as a sacrificial lamb, taking on the punishment of sin. Therefore, this doctrine is firmly rooted in Scripture and is vital for understanding how Christ reconciles believers to God. By faith in Him, we receive His righteousness and are justified before God, confirming the truth of substitution.