Mark Edwards, saying it like it is:
The Gospel is not an ineffable [that is, indescribable] mystery beyond words, but a story—the story of Jesus—that can be articulated and understood in common language.
The proclamation is not the verbalizing of the subjective experience of the believer [“my story”] but the making known of the saving activity of God in Jesus.
Not what disciples think and feel but what they have seen and heard is the subject of the proclamation; “thus we proclaim, and so you believe.” (1 Corinthians 15:11).
Hence one does not proclaim the gospel either in one’s own words or by one’s own powers; rather, one must be sent by Jesus (Mark 5:19, 6:7).