Why is preaching the gospel necessary for salvation?
Answered in 2 sources
Preaching the gospel is essential because God has ordained that His people will come to faith through hearing His Word.
According to Romans 10:14-17, faith comes by hearing, and hearing by the Word of God. God has designed the means of salvation to include the proclamation of the gospel, demonstrating His sovereignty in both the calling of His people and the means by which they are saved. In 2 Thessalonians 2:13, it states that God chose believers to salvation through sanctification of the Spirit and belief of the truth, which includes the preaching of the gospel. Therefore, the preaching of the gospel is not a mere recommendation but a divine necessity for the salvation of the elect.
Commentary