Paul adds a “wrinkle” to the word “gospel” in Ephesians and it strikes me as very close to how Jesus used his favorite expression, “the gospel of the kingdom.” It is found first in Ephesians 2:17 and is also seen in 3:6, 8 and 6:15. The wrinkle is the concept of peace: the gospel is the gospel of peace. Of course, there is a tendency for some to think “gospel of inner peace with God” but that is not what Paul has in mind.

2:14 For he himself is our peace, who has made the two one and has destroyed the barrier, the dividing wall of hostility, 15 by
abolishing in his flesh the law with its commandments and regulations.
His purpose was to create in himself one new man out of the two, thus
making peace, 16 and in this one body to reconcile both of them to God through the cross, by which he put to death their hostility. 17 He came and preached peace to you who were far away and peace to those who were near. 18 For through him we both have access to the Father by one Spirit.

There it is: Paul’s understanding in this text of the gospel work of Jesus is wrapped up and summed up in one word: peace. This peace is made:

1. In Christ (alone).
2. By reconciling Gentiles and Jews.
3. By means of abolishing that which separated them: the law “with its commandments and regulations.”
4. In order to create one people: the church.
5. So Christ, in effect and via the Spirit in the post-resurrection/post-Pentecost time zone, preached peace to Jews and to Gentiles.