Why is it said that only sinners can preach the gospel?

The assertion that only sinners can preach the gospel stems from the understanding that it is a message of grace offered to those who recognize their own unworthiness. Paul identifies himself as the chief of sinners (1 Timothy 1:15), illustrating that only someone who has experienced God’s mercy can effectively communicate its power. Sinners, having been saved by grace, can empathize with others who are lost, offering testimony of God's redemptive work in their lives. The gospel is a message of hope for the broken, therefore, it is fitting that those who have received mercy are called to share it.