was John the only witness on the Bible?

Answer 1

No.

Answer 2

* Assuming you mean 'witness" as "prophecy"

John was the only New Testament scribe, who wrote extensively about what he saw in the future. Bits of and pieces of what he wrote about the future can be found in every book of the New Testament. [In some books, like Matthew, the bits are glaringly obivous. In other books, like Philemon, they are only alluded to.]

In the Tanach, more specifically, the books of the Prophets, one does find extensive passages that have the same subject matter as the Revelation of John.

* If you mean "witness" as compiler, then
# The most probable compiler of the Tanakh was Ezra. [Obviously not the books written after he died.]
# For the New Testament, the timeline on books being written ends either at 70 CE, 100 CE, or 250 CE. [The 70 CE date assumes that Revelations was the last book to be written, and that it was written before the destruction of Jerusalem. The 100 CE date assumes that Revelations was the last book to be written, and was written after the destruction of Jerusalem. The 250 CE date assumes that the entire New Testament is based upon non extant Gnostic texts. There is documentary evidence to support all three positions. The 70 CE date is the only one that can explain the anomolies that the 100 CE and 250 CE dates rely on, for their "proof". ]

* If you mean "witness" as creator of the Canon

The oldest known list of Canonical New Testament books is from Marcion. circa 150 CE. It includes 10 of Paul's books, and the Gospel of Luke.
Irenauenius circa 185 CE gave a NT Canon that is substantially the same as the current one.
Either of those people, or a plethora of later individuals, can be described, with various degrees of accuracy, s the compiler of the NT.

Revelations 22:19 is often considered to refer to the entire Bible. It does not indicte, either directly, or indirectly, which books are canonical. Indeed, a case can be made that the verse refers only to that specific book.

2 Peter 3:16 implies that at least some of Paul's writings are canonical.

1 Corinthians 15:2-4 is an obvious reference to at least one gospel that is canonical. [The question is which are canonical.]

Acts 17:11 probably refers to the Tanakh, but does not rule out an existing NT Canon.

All other references to "Scriptures" in the New Testment appear to refer to the Tanakh.

Thus, Luke has a possible reference to an NT Canon.
Peter and Paul both have clear references to a NT Canon.

And John, whose only reference is ambigious.

Answer 3

No. There is Matthew and over 500 people were eyewitnesses to the resurrection of Jesus. Paul also known as Saul of Tarsus was an eyewitess to him on the road to Damascus. Please be a little more specific.

Answer 4

no he was not. there 2 in rev. and I think any who was a prophet is a witness about the things to come.

Answer 5

No. All the people mentioned really did exist.

Answer 6

Funny thing is many, deceived by many, tend to focus on John, who turned back to Law behind him, telling many others to start reading the Bible in the gospel according to John, which is notably the only "verily verily" gospel account of four, and perhaps the fourth horse in the Revelation(Uncovering) of John the rider Death rode in on, which is followed by hell, perhaps the hell of such endless division. Not to mention who starts reading a book in the midst thereof.

Perhaps the witness of John, who is more beloved (but only according to John), is true (but only according to John). Perhaps it is both true and false, which is to allegory say both grace and law, truth and lie, or two spirits we are later told (by John) to try to know which is witch, since one of twain is notably antichrist.

Perhaps that is why the writings of Luke, who had perfect understanding of all things from the first, follows both the writings of Mark (surname of John) and John, perhaps to set in order things that were out of order.

Perhaps that is why Paul flat out names John as one of three bewitchers of the churches of Galatia; And allegorically alludes John is the thorn in his flesh, sent by Satan(Peter is the only man called Satan in the Bible), to buffet him. So perhaps John is one of three top dogs Paul said to beware of: beware of dogs("evil workers", law workers) since mirroly the reverse of god is as a dog returned to his vomit (as noted by converted Peter).
http://www.godshew.org/RevelatorySermons26.htm

Perhaps that is why John in 3John flatters Gauis(one of the seven angels of the seven churches of Asia, among the seven named who accompanied Paul into Asia in Acts 20:4, written by Luke), and why John favors Demetrius (who spoke against Paul in Acts)... John flatters Gauis in an attempt to persude Gauis over to his side of the Law vs Grace sides war, such division that got ended by "Christ": "the end of the law", who is "our peace who hath abolished the law".
http://www.godshew.org/Revelations7.htm#22

Perhaps John subverted churches, as the bishop of popish Peter over the churches of Asia from Ephesus, in opposition to Timothy whom Paul sent to be bishop over the churches of Asia from Ephesus; as if bishop vs bishop in a spiritual chess game. Perhaps Timothy even got suck punched by John, got sorely depressed, but recovered from it, as noted in Hebews 13:23.

Perhaps the Revelation(Uncovering) of John isn't even written by John, but rather Pauline written as a spoof on John who turned back to the law behind him, and "sent unto John", also being sign-ified as whom from, notably by the last verse being the saluation(token in every Pauline epistle) of Paul, notably by his own hand.
http://www.godshew.org/Revelations3.htm
http://www.godshew.org/Revelation.htm#Author

The "grace" of our Lord Jesus Christ with you all. Amen.