How do we know that God's grace is sufficient for believers?

The sufficiency of God's grace is profoundly evident in the resurrection of Jesus Christ, as illustrated in the story of Thomas, who initially doubted the resurrection. Despite his rebellion and lack of faith, Jesus appears to him, directly addressing his doubts with grace and mercy. This act of coming to Thomas demonstrates not only the power of God to overcome our hardened hearts but also His willingness to meet us in our unbelief and provide assurance through His wounds. The grace of God transforms Thomas from a doubter to a believer, reaffirming that no amount of rebellion or doubt can thwart the reach of God's redeeming love and grace, which gives believers peace and a renewed spirit.