Gospel / [εὐαγγέλιον](https://www.blueletterbible.org/lexicon//esv/tr/0-1/) simply means "good news" and predates Christianity. After Jesus the term began to accrue increasingly specific theological meaning, particularly as defined by Paul, but that doesn't mean this would be how Jesus or the Apostles would ever have intended the term in the Gospels. In the text of Luke, the εὐαγγέλιον is introduced by Jesus in what has been described as his 'Kingdom Manifesto' in Luke 4: > The Spirit of the Lord is on me, because he has anointed me to preach **good news** to the poor. He has sent me to proclaim release to the captives and recovery of sight to the blind, to set free the oppressed, to proclaim the year of the Lord’s favor. Luke 4:18-19 CSB https://bible.com/bible/1713/luk.4.18-19.CSB Jesus reiterates the term later in the same chapter, specifying that the good news was of the 'Kingdom of God': > But he said to them, “It is necessary for me to proclaim **the good news about the kingdom of God** to the other towns also, because I was sent for this purpose.” Luke 4:43 CSB https://bible.com/bible/1713/luk.4.43.CSB And from here onwards Jesus' teaching centres on the Kingdom of God, including many of the parables captured in Luke. So when the disciples were preaching the "good news", it would have been about the Kingdom of God and that it had arrived on earth.