We don't have Jesus actual words because he wrote nothing down as you say. Is it not possible that he was virtually illiterate ? that all his knowledge came from listening to others ? so he actually "wrote nothing" ?
Even the words we have which are recorded as though he actually spoke them we do not have reliable evidence for. The Gospels were written many decades after the life of Jesus, and we only have copies of many copies of those, and then they are translated.
Textual criticism perhaps does well at getting to what was probably written originally, but how trustworthy are the originals, even if they existed ? they contradict eachother in a number of places which does not engender confidence.
I doubt that anyone wrote down Jesus sermons and teachings close to the time, so we have frail human memory, as well as the writers agenda, and the lack of Provenance for the manuscripts all to contend with when trying to determine anything he did say.
How strange is that, if his words were Truth and Life as is claimed in the Gospels ? Surely it would have paid God to preserve these words properly , not to so carelessly lose them ?