From The Mission of God's People by Christopher Wright:
What is the gospel, then, for Paul?
It is historical and also ecclesial; that is, includes facts of history about Christ and the reality of a new humanity in Christ.
It is faith and obedience.
It is a message that must be heard and a life that must be seen.
It is personal and cosmic.
It is above all 'the gospel of God' - the grace of God, the promise of God, the faithfulness of God, the salvation of God, the Son of God, the people of God, and the glory of God.
Our whole gospel, then, must be drawn from the deep well of the whole Bible, and our mission must be integrated accordingly around its great resonant narrative of saving grace, its transforming demand for, and promise of, covenantal obedience, and its vibrant hope and vision of a new creation in which righteousness dwells, for God will dwell there with his redeemed humanity from every nation.