"For we did not follow cunningly devised fables when we made known to you the power and coming of our Lord Jesus Christ, but were eyewitnesses of His majesty." (2 Peter 1:16)
The very first thing that should compel you to preach the Gospel of Jesus Christ is the truth of the Gospel. The Gospel isn't an assumption or some fairytale. This Gospel is truth.
Secondly, the content of the Gospel and what it says is most compelling: that Jesus Christ came into this world to save sinners, and that He was, and is, the Son of God in truth-- He is God in flesh. Moreover, He was crucified on the Cross, and He died for us. He was buried, and God raised Him from the dead, and He's alive today. His death on the Cross was a sacrifice for the sins of the world.
When Jesus died, we died with Him; when He was buried, we were buried with Him; when God raised Him back to life, we were raised together with Him. Now because He lives, we live. Hallelujah! These are our convictions about Christ and about the Gospel!
(2 Corinthians 5:21)
"For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him."
Think about it: the One who knew no sin at all took all the blame, was made sin for us, so that we might be made the righteousness of God in Him. Where we are dead to sin, now in Him we live! What a message! There's nothing life it in the world, it's the greatest story ever told-- the greatest news of all time!
Now, to think that this is the Gospel that Abraham looked forward to, that Isaac and Jacob and the patriarchs looked forward to and prophesied about-- to think that this is the Gospel that we've embraced, that has become real to our spirits, is overwhelming. It's an unending song, an ever-flowing stream of unending joy.
When you think about Jesus and what the Gospel means, and all that He's done for you, you should be compelled to preach it more than ever. Refuse to be quiet-- tell it everywhere!
I'm compelled by the truth of the Gospel to preach it around the world. The zeal of the Lord propels me to proclaim liberty to the captives, and to turn men from darkness to light, and from the power of Satan to God. The Lord Himself is effectually at work in me-- His power and desire-- to fulfill His delight and please Him in all things. Amen.
Further Study: Romans 1:16; 1 Corinthians 9:16-23