Have you ever attempted to define it?
Sure, Websters has their modern definition HERE. But compare and notice HERE how the Websters definition has changed over the past 190+ years.
The word of God says that Jesus is the same yesterday, today, and forever (Hebrews 13:8). Yet, many today have their own personal definitions about what the gospel is and what the gospel is not. As with Websters, it is easy to see that the positions of men are as shifting sand ... unstable and ever-changing.
In order to be sure, the foundation of faith must be built on the solid rock of Christ Jesus (ref. Matthew 7:24-27).
So, without further delay, let us see together what the gospel is according to the word of God.
The gospel of Jesus Christ is: "the power of God unto salvation" (according to Romans 1:16).
From this key scripture, we can begin to see the truth about the gospel. First of all, it is "the gospel of Jesus Christ." Without Jesus Christ, the gospel is not the true gospel. One could even say that the gospel is Jesus Christ. However, that is not exactly what the word of God says. The word of God says that the gospel is "of Jesus Christ."
In fact, looking again at the 1828 Websters definition, we see that the gospel...
It is called the gospel of God. (Romans 1:1) It is called the gospel of Christ. (Romans 1:16) It is called the gospel of salvation. (Ephesians 1:13)
That is what it is called ... but not what it is. Again, according to the word of God (Romans 1:16), it is "the power of God unto salvation."
This begs at least two further questions ...
What is "the power of God?" ... and ... What is "salvation?"
These two questions will be investigated in further studies.
However, for now, we can rest (according to the word of God) in the fact that the gospel of Jesus Christ is the power of God unto salvation. And, we can view in detail the explanation of the practical nature of the gospel that The Apostle Paul provided for the Thessalonians here: OUR GOSPEL.
God bless you. To be continued...