In spoken word:
Tim Keller answering “What is the Gospel?” to a skeptic:
What about my doubts?
In Mark 9, a man asks Jesus to help him with his unbelief. We too can ask Jesus to help us with our unbelief. He’s also given us the church to help us in our faith.
The core message of Christianity is not how to be a good person or how to believe in God. Scriptures tell us that we are broken and unable to fix ourselves by our own effort and merit.
The Gospel is not giving God a good record. I don’t have a good record. I’m a moral failure. But the good news is that a good record is a gift by God’s grace. This is the nature of what biblical salvation is.
What does it mean to be a follower of Christ?
1) Acknowledge that you have trusted in yourself or other things rather than God.
2) Repent from trying to fix your problems by yourself.
3) Trust in the person and work of Jesus Christ on the cross and His resurrection.
4) Follow Jesus by knowing Him as revealed in Scripture in regular relationship with other Christ-followers (ie. the church).
The Gospel is the message that God has lovingly and sacrificially rescued sinful individuals into right relationship with himself through the person and work of Jesus Christ, towards the eventual destruction of all the effects of sin in the world.