Why is the doctrine of justification critical for a church?

Justification is a foundational doctrine in Reformed theology, as it addresses how sinful humanity can be reconciled to a holy God. Martin Luther remarked that a church stands or falls by its understanding of justification, meaning that misunderstanding this doctrine can lead to grave errors. Justification, as articulated in Romans 3:28, is by faith apart from works of the law, which underscores the sufficiency of Christ’s righteousness imputed to believers. The doctrine highlights that it is through Christ's atoning work that believers are declared righteous, instilling both hope and assurance. The early church's preaching was centered on this truth, reinforcing the core message of salvation through faith in Christ alone.