Jesus preached the gospel (Mk 8:35).  But he didn’t preach his death, burial and resurrection.  In fact he often silenced the disciples about these things as well as about his identity.  It wasn’t time.   The gospel was also announced to Abraham, and that was a few years before Jesus’ death, burial and resurrection (Gal 3:8)

So if he preached the gospel then what gospel did he preach?

Paul spells it out to us.

⁷ Understand, then, that those who have faith are children of Abraham. ⁸ Scripture foresaw that God would justify the Gentiles by faith, and announced the gospel in advance to Abraham: “All nations will be blessed through you.”^{[b] 9} So those who rely on faith are blessed along with Abraham, the man of faith.

This is the gospel:  Man is justified by faith [through grace enacted by the death, burial and resurrection of Jesus Christ).

Justification by faith.

For those before the Christ, it was a looking towards Him.
For those of us after Christ, it is the looking back.

Christ made it possible for us to be justified by faith.

Not works.
Not laws.
Not following good principles.

Just faith in Jesus for our salvation.

He’s saved us.  We didn’t.
He redeemed us.  We couldn’t.

That’s the good news.