Msgr. Charles Pope (how’s that for a name?) explains:
3. The Gospel is not merely noetic (informative); it is dynamic (transformative). God said, “Let there be light,” and there was light. Thus when God says “Be holy,” His words contain the actual power to effect what they announce, provided we receive them in faith.
4. The Gospel is no mere written word. The Gospel is Jesus Christ, the Word made Flesh. Therefore the Gospel saves all who receive it (Him) with faith and heed its warnings and teachings with the obedience of faith.
Thus, the term “gospel” means more than “good news.” And given our cultural setting and its presuppositions related to the word “good,” the notion that “gospel = good news” can be downright misleading. It is better and richer to understand the term “gospel” to refer to the life-changing and transformative utterance of God, which is able to save us if we obey its demands in faith. It is in fact Jesus Himself who is the Word made Flesh. Perhaps this is less memorable, but it is more true and less misleading.
But given our historical setting post-fall, good news that promises we will be saved if we obey God’s commands doesn’t sound very good. (Why should the gospel be only “Good News” instead of like awakenings “Great News” or revolutions “Glorious News”?) That’s why the first Protestants (read Lutherans) were known as evangelicals. Obedience Boys take note.