The Gospel is a Person, the God-Man Jesus Christ. Mark makes this point in the opening verse of his book:

“The beginning of the Gospel about Jesus Christ, the Son of God.” (Mark 1:1)

“Gospel” is a translation of “Evangelion” literally meaning, “good news”. It refers to the message about Jesus’ life, death and resurrection and the resulting benefits that come our way. So, understanding the Gospel begins with understanding who Jesus is.