How do we know salvation is truly by grace alone?

The doctrine of salvation by grace alone is fundamental to Reformed theology, grounded in Scriptures such as Ephesians 2:8-9, which states that we are saved by grace through faith and not by our works. This doctrine highlights that salvation is a gift from God, not something we can earn or choose on our own. According to Proverbs and the broader biblical narrative, true understanding of this grace comes only when God imparts understanding to our hearts through the Holy Spirit. The finished work of Christ on the cross ensures that salvation is fully accomplished, leaving no part of it to human merit. Thus, our acknowledgment of our need for grace and the cry for mercy is itself evidence of His sovereign grace at work within us.