13. What is the gospel of the Lord Jesus Christ?

The gospel (or good news) of Jesus is the fact that He came to seek and save those who were lost. This salvation is made possible by His death, burial and resurrection.

~John 3:14
14. And Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up:
15. That whosoever believeth in Him should not perish, but have ever lasting life.
16. For God so loved the world, that He gave His only begotten Son, that whosoever believeth in Him should not perish, but have everlasting life.

The world through Him might be saved.