The gospel is the belief that the creator God, sent his son Jesus, to be a sacrifice for our sins; so that we could be with him forever. The wages of sin is death (Romans 6:23), and Jesus paid that price for us, in obedience to God the father (Mathew 26:39) so whoever believes in him shall not perish but have everlasting life (John 3:16). This belief brings the forgiveness of our past transgressions, and the removal of condemnation of our sin before God.
That means every lustful thought, spit in his face. Every hateful thought towards our fellow man, a Roman scourge to his back. Every lie, great or small that crosses our lips, a crown of thorns on his head. Every self serving and self glorifying action or thought, our cry to “CRUCIFY HIM”.
His reply; “father, forgive them, for they know not what they do.” (Luke 23:34)
That’s the gospel. and for that reason, I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. (Romans 1:16)