Summary of the "gospel"?:
Jesus the Christ, the God-Man, Son of God, Son of Man, THE Divine Messiah, TRUE Man, TRUE God, (many names/titles) etc...
has come down / was sent down from the heavenly realms to earth to SAVE Man from eternal spiritual death (separation from God).
GOOD NEWS! GLAD TIDINGS!
"the gospel" >used only in the NT!<...Greek 2098...euaggelion...
as the Messianic rank of Jesus was proved by his words, his deeds, and his death,
the narrative of the sayings, deeds, death, and resurrection of Jesus the Christ
came to be called the "gospel" or "glad tidings".
Mark 1:14-15 (NASB)...Jesus Preaches in Galilee
Now after John (the Baptizer) had been taken into custody, Jesus came into Galilee, preaching the "gospel of God",and saying,
“The time (prophecy) is fulfilled, and
the "kingdom of God" (Jesus) is AT HAND; (Jesus the Divine Messaiah has COME!)
Repent (turn to God) AND BELIEVE in the (this?) "gospel".”
Jesus was the personification of the "Kingdom of God".
Luke 17:21...nor will they say, ‘Look, here it is!’ or, ‘There it is!’ For behold, the "kingdom of God" is (standing) in your midst.”
GOSPEL of the KINGDOM / GOSPEL of GOD
Matthew 4:23 (NASB) (see also Matthew 9:15; Matthew 24:14)
... [ Ministry in Galilee /synagogues + Prophecy of the end of the ages]
Jesus was going throughout all Galilee, teaching in their synagogues and
proclaiming "the gospel of the kingdom", and
healing every kind of disease and every kind of sickness among the people.
Ephesians 1:13..In Him, you also, after listening to the message of truth,
the gospel of your salvation — having also believed, you were sealed in Him with (God) the Holy Spirit of promise,
1 Timothy 1:11...according to the glorious gospel of the blessed God, with which I have been entrusted.