How do we know God's saving power is effective?

The effectiveness of God's saving power is primarily seen in the transformation it brings to sinful hearts. As stated in Ephesians 2:1, we were dead in our trespasses and sins, illustrating our complete inability to come to God on our own. However, when the call of the gospel is proclaimed, it is through God's sovereign grace that we are made willing to believe. This parallels Romans 8:30, which claims that those God predestined are called, justified, and glorified. Thus, God's saving power is proven true as it accomplishes His purposes in the hearts of the elect, leading them to salvation.