“it is nothing other than the gospel, indeed an exhaustive statement of the content of the gospel, namely that Christ must be crucified, that the Messiah had to die in order for sinners to be forgiven by God–was the very thing that scandalized the Jews and was treated as folly by the Greeks (1 Cor. 1:23). The gospel was an “offense” to them and “foolishness” because in the cross God did precisely the opposite of what they expected him to do. ”

— Ralph Martin, Philippians: Tyndale New Testament Commentaries (Downers Grove, IL: IVP, 2008), 223.