lack of understanding the truth does not make it a different truth.
He pointed them all the way back to Moses, beginning with Genesis, explaining through things written long before the crucifixion, not afterwards, how that if they had understood and believed what was written then all of these things, His incarnation, His life, His death, His burial, His resurrection, His ascension and His return -- they would not have been ignorant.
He didn't change the gospel when He opened their hearts to understand.
just because you don't understand the chemistry of the things you eat being transformed into nourishment for your body, doesn't make it "not food"
do you really not comprehend this?