Do we know if John the apostle(or any of the apostles for that matter) was a real person or not? Is there any proof that we know is credible? and if he wasn't real, do we know who really wrote the book of revelation?
No. But based on the highly legendary nature of the character called John, it would be reasonable to assume that some person did something which triggered the legend. For example, John is associated with a foreign word "baptism" which, had it been a Jewish rite, would have had a Hebrew or Aramaic name. So right off the bat we have to question why the Gospel of John begins with him baptizing in the wilderness, since no one would have understood what that means. If they had a good knowledge of Greek they might understand that it means he was bathing, but they would have no reason to associate this with a Jewish rite. The discovery of the ruins of Qumran, near where the Dead Sea Scrolls were found, revealed underground bath houses, which were the consequence of their livelihood, which was quarrying rock. The Qumranis were a sect of disaffected Jews who left Jerusalem and went into "the wilderness" to escape the bickering between sects like the Sadducees and the Pharisees of Jerusalem, where they could escape these material distractions and live a contemplative life. These people were the Essenes. It stands to reason then, that the story of a man baptizing in the wilderness is possibly a legend that stems from a metaphorical reference to the Essenes at large, or else there might have been an Essene named John who for some reason became a central figure in the second version of the Jesus story, so different from the Synoptic versions, which we call the Gospel of John. But of course the legendary mangling of facts and events leaves this completely uncertain. I personally believe that the use of logos in the opening of John, commonly translated "In the beginning was the word and the word was with God and the word was God" is a concept borrowed from Greek Stoicism. That is, I believe this translation is incorrect. I would translate "in antiquity logos pertained to theos; logos and theos were identical" which takes us into Stoic beliefs. It also appears that the Essene philosophy had much in common with Stoicism. That leaves it to decide if there were a branch of Hellenized Jews who were so steeped in Stoicism that their own legend about Jesus took on its own separate oral tradition. The main proof that the author of Book of Revelation is not the same as the author of the Gospel of John is found in the exegetical analysis, which concludes that they are probably not the same authors. The earliest documentation of this was by the Alexandrian bishop Dionysius, sometime before his death in 165 CE. No. This may have been a book that escaped the stage of oral tradition and was directly committed to text. Because of the highly hallucinatory nature of the visions described, it is reasonable to assume that a person with brain damage authored the bizarre story. It has been suggested that the author may have been epileptic. In the last decade or so, there has been some neurological evidence to correlate hallucinations and "the religious experience", as a syndrome of some seizures, with patients likely to describe bizarre visions.
Luke's The Rich Man and Lazarus story has the rich man suffering in Hades after his death. He asks Abraham to send Lazarus, who is also dead, to go and visit the rich mans family, to warn them to change their ways. Abraham refuses, saying even an appearance of the dead will not convince people. The story of Lazarus in John appears to be correcting this idea, an appearance of the dead will convince people. This is just one example of John borrowing from the other gospels, which tells us it was written last, and was probably started at the very end of the first century AD, or the very beginning of the second. This tells us it was not written by the apostle, despite his alleged long life. Furthermore, chapter 21 was not mentioned by Tertullian at the end of the second century, suggesting the gospel was still being written almost 100 years later. The Book of Revelations, as noted by Aqueous Id, was not written by the same author. As to other apostles, apart from the dubious alleged relics, the only reference would be to Cephas in one of Paul's letters. It is unlikely that the things done by Cephas recorded in the gospels are historical.
