The Briefing Note:

The Gospel is not a suggestion—it is a Sovereign Announcement. In the 1st century, an evangelion was the official news that a new King had taken the throne. In the Book of Acts, the apostles weren't sharing a private religious opinion; they were acting as heralds for a global "Strategic Pivot." They announced that a new Sovereign—Jesus—had been installed as Lord of all, a claim backed by the forensic evidence of the Resurrection.