Most religious scholars don’t even think that the four canonical Gospels were written by Mark, Luke, Matthew, and John themselves, much less God, and are instead based loosely on oral tradition, compilations of miracle stories, and so on. I don’t agree with that, to be clear, but I can convey to you what your average biblical scholar thinks.
Anyway, the fact of the matter is, the theme of Christ saving all of mankind or all who believe or some other similarly universal variation, is replete with the four “canonical” gospels. It’s well-understood that this is the case. Only people who haven’t even read them don’t know about this. It appears over and over again in various forms.
Xenophon even tries to argue that everything in Mark 16 past verse 8 doesn’t count. He desperately, desperately wants Christianity to be a Whites-only religion, to the point of outright rejecting chunks of KJV as scripture at all.