How do we know that the gospel is powerful to save?

The power of the gospel to save lies in the divine authority behind it. As stated in Romans 1:16, 'For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes.' This reflects that God actively uses the gospel to effect salvation in those He has chosen. The Apostle Paul emphasizes this in his writings, illustrating that the message he preached was the means God uses to open the eyes of the spiritually blind and regenerate the hearts of sinners, bringing about faith and salvation.