How do we know grace alone is sufficient for salvation?

The doctrine of salvation by grace alone is foundational to Reformed theology and is confirmed by multiple passages in the New Testament. For instance, Ephesians 2:8-9 clearly states that it is by grace that we have been saved through faith, and not by works, so that no one can boast. This underscores the idea that human effort cannot contribute to our salvation—only God's grace can do that.

Additionally, Romans 3:20-28 emphasizes that no one will be declared righteous in God’s sight through the works of the law, but only through faith in Jesus Christ. This strong biblical evidence demonstrates that our standing before God is firmly rooted in Christ's righteousness and not in our own actions or merit. Furthermore, 2 Timothy 1:9 expresses that God has saved us and called us with a holy calling not according to our works, but according to his own purpose and grace. All these passages collectively affirm the sufficiency of grace for salvation and provide believers with assurance of their eternal acceptance in Christ.