What good news is proclaimed in the books called Gospels?

The good news is centered on the person and ministry of our Lord and Savior Jesus Christ, from his conception to his death on the Cross, resurrection, ascension, and second coming. The very word appears in Gabriel’s annunciation, “I am Gabriel who stands near before God. I was sent to speak to you and to bring you this good news” (Luk 1:19; see Q100), and in the angel’s proclamation at Bethlehem:

Be not afraid; for behold, I bring you good news of a great joy which will come to all the people: for to you is born this day in the city of David a Savior, who is Christ the Lord. (Luk 2:10–11)

To understand the good news of Christ’s coming, we must first be aware of the ‘bad news’ of our enslavement to sin and death. The great High Priest, who is the Word (Logos) of God and Lord, entered our world and took flesh from the Theotokos and Ever-Virgin Mary, to save, that is, to deliver and rescue, us from “the one who has the power of death, that is, the devil,” and to “free those who all their lives were held in slavery by the fear of death” (Heb 2:14–15; see Q155, Q168).

The books of the Gospel proclaim the good news of the ineffable love of God the Father in Christ Jesus:

For God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life. Indeed, God did not send his Son into the world to judge the world, but so that the world should be saved through him. (Joh 3:16–17)