What is the Gospel of Yeshua / Jesus?
Same as Isaiah's gospel, same as Daniels gospel, same as Jonah's gospel, same as Moses' gospel.
John 3:16.......Believe in me you will be saved. What does believe in Jesus mean? Even the demons believe in him, they feared him, they even obeyed him when he cast them out. HOWEVER, the demons chose not to obey YHWH, they pursued their own pleasures instead.
The servants (prophets) and Son (Jesus) all had the same job. (they all preached the same sermon): OBEY YHWH / GOD!!