The simplest definition for the word Gospel is: the message of who
Jesus is and what He did.
In the New Testament Greek, the word is ε?αγγ?λιον, euaggelion (pronounced: yoo-ang-ghel’-ee-on), and is literally translated, “good news.” 1
The good news of the gospel is that Jesus lived a life of perfect righteousness, and of perfect obedience to God, not for His own well being but for His people. He has done for me what I couldn’t possibly do for myself. But not only has He lived that life of perfect obedience, He offered Himself as a perfect sacrifice to satisfy the justice and the righteousness of God. 2
Therefore, to believe the gospel, is not only to accept the awesome truths that 1) God is holy, 2) we are hopeless sinners, 3) Christ died and rose again for sinners, and 4) this great salvation is enjoyed by faith in Christ—but believing the gospel is also to treasure Jesus Christ as your unsearchable riches. 3
What makes the gospel “Gospel” is that it is completely unmerited and solely an act of God’s grace and mercy. Furthermore, it brings a person into a life-changing relationship with God the Father, through the power of the Holy Spirit, because of what Jesus accomplished through his life, death, burial, and resurrection.
With that in mind, you can understand why, as a church, our services will look much more like a party than a funeral—because we have something to celebrate. God loves us and has changed our lives. We’ll spend eternity with Him, and we want Him to use us to tell as many other people about this good news as we can.
1http://biblehub.com/greek/2098.htm
2http://www.ligonier.org/blog/what-is-the-gospel/
3http://www.desiringgod.org/articles/what-is-the-christian-gospel