John was martyred - as tradition holds - back with the James - Peter .. and the others. No one heard of the guy wandering around in the Gospel of Mark or Matt .. and obviously we should hear mention of him would he had been still living .. for certain in Luke as well .. the synoptics.
Regardless .. dead or not .. the Gospel of John .. was not written by John the Disciple of Jesus
Robert Kysar writes the following on the authorship of the Gospel of John (
The Anchor Bible Dictionary, v. 3, pp. 919-920):
There is a case to be made that John, the son of Zebedee, had already died long before the Gospel of John came to be written. It is worth noting for its own sake, even though the "beloved disciple" need not be identified with John, the son of Zebedee. In his ninth century
Chronicle in the codex Coislinianus, George Hartolos says, "[John] was worth of martyrdom." Hamartolos proceeds to quote Papias to the effect that, "he [John] was killed by the Jews." In the de Boor fragment of an epitome of the fifth century
Chronicle of Philip of Side, the author quotes Papias: Papias in the second book says that John the divine and James his brother were killed by Jews. Morton Enslin observes (
Christian Beginnings, pp. 369-370): "That PapiasÂ’ source of information is simply an inference from Mark 10:35-40 or its parallel, Matt. 20:20-23, is possible. None the less, this Marcan passage itself affords solid ground. No reasonable interpretation of these words can deny the high probability that by the time these words were written [ca. 70 CE] both brothers had 'drunk the cup' that Jesus had drunk and had been 'baptized with the baptism' with which he had been baptized." Since the patristic tradition is unanimous in identifying the beloved disciple with John, at least this evidence discredits the patristic tradition concerning the authorship of the Gospel of John.
www.earlychristianwritings.com
more can be found at the above site.
Jesus words would however been available once the Gospel of Mark was distributed .. if written in 65 AD .. distribution is going to take awhile .. but let us assume word of mouth was around by this point .. or shortly there-after. From the Death of Jesus ~ 30 AD to 65 AD is a fair chunk of time that folks would be without the words of Jesus .. Some may have written things down after the Death of Jesus .. but these one off writings would not be in much circulation .. if such existed at all.. The Gospel of Mark is said to be penned by a follower/ interpreter for Peter. Peter unable to read or write of course .. as was the case with John -- The author of Matt uses all of Mark .. sans a few passages he finds dispairaging towards Jesus and/or the disciples .. The author adds some other stuff which perhaps he obtained .. some scratchings that someone had done .. The Sermon on the Mount more complete perhaps.
Thats all we have for the words of Jesus as per the completion of Matt ~ 70-90AD -- presumably the writings of Paul had begun to circulate but these do not tell us aught of Lord Jesus or his words.