How do we know God's call is effective in salvation?

The sermon emphasizes that God, in His sovereignty, effectively calls His chosen people through the preaching of the gospel. While creation itself offers a witness of God's power (Romans 1:20), it is the specific message of the gospel that calls the elect to faith. In Jeremiah 3:15, God promises to provide pastors after His own heart to preach truth. This demonstrates a clear biblical principle that faith comes by hearing, and God uses the faithful preaching of the Word to save His people from spiritual darkness.