What is the Gospel of the Kingdom?

[bishoph]

Throughout three of the synoptic Gospels there is repeated reference to Jesus preaching the "gospel of the Kingdom." Nearly all of these references were prior to the death burial and resurrection of Jesus Christ. So................................................ ... for all of our scholars..... what was the "Gospel of the Kingdom of God" that Jesus was preaching?

Matthew 4:23, Matthew 9:35, Matthew 11:5, Matthew 24:14, Matthew 26:13
Mark 1:15, Mark 13:10, Mark 14:9
Luke 4:18, Luke 7:22, Luke 9:6, Luke 20:1