How do we know God's grace is enough for sinners?

The narrative of Peter's denial and subsequent restoration serves to emphasize that God's grace is sufficient for even the gravest failures. Peter, despite his denial, was not cast away; instead, he was upheld by the grace of God. His tears of sorrow and bitter weeping after denying Christ indicate his remorse but are not the basis for his redemption. It's the grace of God that restores him. The assurance is found in passages like Proverbs 24:16, which speaks to the righteous being lifted up after falling. God's unchanging nature ensures that He preserves His people, offering forgiveness and restoration regardless of our failings. Ultimately, it underscores the key truth of sovereign grace—that salvation is entirely dependent on God and His mercy toward sinners.