Recently, I have posted a couple of articles trying to articulate what I believe the gospel is, especially as noted in the proclamation of Jesus in the four canonical Gospels. I can only imagine the gospel being clearly proclaimed by the eternal Messiah-Son of God. You can read the articles here – post 1 and post 2.
Of course, I will not deny some influence from what people like N.T. Wright have been putting forth in understanding the gospel within its historical, second-temple, first-century context. But I also very much appreciated George Ladd’s The Gospel of the Kingdom some 10 or 12 years ago when it was passed on to me by my pastor-spiritual father.
So, below is a two-and-a-half-minute excerpt from Wright summarising the gospel. From my understanding, this is solid, New Testament teaching.