We don't know if the Injeel (the Gospel of Jesus pbuh) ever existed in written form - so far no Christian authority has been able to say with any confidence that such a document was ever in existence...
...does that mean to say that the Gospel of Jesus pbuh never existed?
IN an age where most people didn't know how to read nor write, the Oral Tradition of memorising entire genealogies and accounts of deeds from ancestors was the common norm. Thus, the Gospel of Jesus pbuh would have also entered this Oral Tradition.
Even up to 7 centuries later, the Muslims were memorising their holy book, the Quran, to heart. Proving that the Oral Tradition in ancient times was a factor we do not consider in our historical approach today.
The injeel - Gospel of Jesus pbuh existed in the hearts of those who had memorised it - but it remains unrecorded as a written work.
Instead, what we have is the Chinese Whispers Version of the Gospel of Jesus (pbuh) in the versions of the bible according to "Matthew, Mark, Luke and John" and what makes it even harder to authenticate those is the very fact that no one can with any certainty say they knew who these four characters really were...
...Let's try a quick exercise in logic.
WOuld you trust a book written by someone who never left their last name? Obviously not... if said author lacked the conviction of their own propagations, they'd not attribute that work directly to themselves in fear of ridicule.
Scimi