The first verse of the gospel of Mark in the Greek looks like this:
“Ἀρχὴ τοῦ εὐαγγελίου Ἰησοῦ χριστοῦ.”
Notice anything interesting about it structurally? What I notice is that at the center is the word that we translate as “gospel” (εὐαγγελίου). Keep the gospel center is a very wise approach when you have to testify.