Do you know what the gospel is?
Are you going to tell me? :^)
My understanding of the Gospels: They are fundamental Truth — direct testimony from persons who were intimately associated with Jesus personally, in His walk as a human being in this world.
That is to say, these men — Matthew, Luke, Mark, and especially John — the beloved apostle — testify and witness to the Logos of God, the ultimate criterion of all that exists in God's Creation. Compared to which St. Paul was a secondary source — though an eminently brilliant and completely faithful one, praise ever be to his name!
(Paul was not a direct witness of anything, except his own de-horsing on the Road to Damascus, with all subsequent complications....)
Do you see the problem differently?