What is the "gospel" supposed to mean? What is the gospel supposed to mean? In what ways can it be used? What do Christians generally mean when they use the term "gospel"?
The word "gospel" is the Old English word for "good news" or "glad tidings" and has several different uses. It comes from the Greek word εὐαγγέλιον, euangelion (eu- "good", -angelion "message"). As an adjective, it is used in gospel choir or gospel music, perhaps to refer to the African American spiritual Christian hymn. As a noun, it is used in the phrase "to preach the gospel" or "to share the gospel", which means to evangelise. Evangelism is interpreted by many Christians to be a good thing, because they may say:


The purpose of the gospel is to win souls to Christ.
The purpose of the gospel is to enter the kingdom of God in God's plan or make life on earth as if it were the kingdom of God when it would be fully realized.
The gospel is to help human beings become the most fully alive that they can be.
The gospel books is to describe what Jesus has done on earth and how his works are significant to Christians, giving Christians a new identity apart from Judaism, and emphasizing especially on the significance of the resurrection. 


To outsiders of the faith, it just means to convert to Christianity. 

Upon conversion to Christianity, it is expected that the person would be baptized. The means of baptism, however, varies from denomination to denomination. Refer to the conversation between Nicodemus and Jesus about baptism in John 3:1-10.

In short, there are two ways that gospel may refer to: (1) the act of converting to Christianity or (2) the life of the ideal Christian. Plus, the life of the ideal Christian may be a method to evangelism, an attempt to convert non-Christians into the Christian faith by making the Christian faith sound very attractive. Refer to "lifestyle evangelism".