First, let's look at a text from Isaiah:
52: 7 How beautiful on the mountains are the feet of those who bring good news,*
who proclaim peace,
who bring good tidings,
who proclaim salvation,
who say to Zion,
"Your God reigns!"
Okay, so we can see that the "good news" here seems to have something to do with the god of Isaiah and his audience being in charge the way a ruling king is in charge and that God sending a message of peace and salvation (in this case from exile and subservience to Babylon, who had conquered them in 587 b.c.e.). I think most people would agree that if any such deity WAS in charge, that a message of peace and salvation would be good news (unless one was Babylonian or Persian perhaps, since they conquered Babylon).
Now, Isaiah 61:1-2 picks up the gospel language:
"The Spirit of the Sovereign LORD is on me, because the LORD has anointed me to preach good news to the poor.
He has sent me to bind up the brokenhearted, to proclaim freedom for the captives and release from darkness for the prisoners, to proclaim the year of the LORD's favor, the day of the vengeance of our God."
This get more specific and more complicated. The good news is the advent of a particular year and day. It is the announcement of the year of Jubilee from Leviticus in which the Israelites were mandated to cancel debts and return land that had been sold or traded to its original owners. God's economic plan for Israel seems to have been a cycle of 49 years of fairly laisse-faire dealings followed by a decisive punch to the "reset" button. Anyway, tt seems clearer here that the good news is good for some people and not others. Some will get favor and freedom and others vengeance? Some people will get their stuff back and others will lose the stuff that they had accumulated.
Getting slightly ahead of myself, This second passage is the one Jesus reads (and announces the fulfillment of) in Luke 4, BUT Jesus leaves OFF the "vengeance" line and offers some upsetting commentary to his audience that in the days of the prophets of Israel, God's favor had been extended to people outside the community of Israel, even to a military leader of their enemies, even when there were those inside the community that needed God's favor in the same way and didn't get it. Whoops. Did God mis-fire? Jesus seems to indicate that it was intentional.
Next we'll look at a passage from Daniel and an ancient Roman account of the evangelion.